Given below are two statements : Statement I : lim _ mathrm x rightarrow 0 left(frac tan^ - 1 mathrm x + log_ mathrm e sqrt frac 1 + mathrm x1 - mathrm x - 2 mathrm xmathrm x ^ 5right) = frac 25 Statement II: lim_xto 1left(x^frac21 - xright) = frac1e^2 In the light of the above statements, choose the correct answer from the options given below:

Solution & Explanation

### Related Formula log(1+x) = x - fracx^22 + fracx^33 - dots lim_x to a u^v = e^lim (u-1)v ### Core Logic Verify Statement I via high-order Taylor polynomial series tracking, and determine Statement II values by resolving standard exponential limit properties. ### Step 1: Expand Statement I Sequence Polynomials tan^-1x = x - fracx^33 + fracx^55 - dots frac12[ln(1+x) - ln(1-x)] = x + fracx^33 + fracx^55 + dots Summing terms together and subtracting 2x leaves: lim_x to 0 frac2x^5/5 + dotsx^5 = frac25 quad text(Statement I is true) ### Step 2: Verify Statement II Limit Power Structure Evaluating the 1^infty form configuration style: e^lim_x to 1 left(frac21-xright)(x-1) = e^-2 = frac1e^2 quad text(Statement II is true) ### Step 3: State Conclusion Both statements are correct. ### Pattern Recognition When a limit features a power factor of 5 in the denominator, you must track expansion variables through the 5th degree term to guarantee accuracy. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Limits

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Q68 jee_main_2025_24_jan_evening Number of Real Solutions of Equations
The number of real solution(s) of the equation x^2+3x+2=min\|x-3|, |x+2|\ is: [cite: 3396, 3397]
  • A. 2
  • B. 0
  • C. 3
  • D. 1

Solution

### Related Formula The function min\f(x), g(x)\ chooses the lower vertical path between the two curves at any coordinate x. ### Core Logic Analyze the conditions for the \right-hand function min\|x-3|, |x+2|\: - The intersection of |x-3| = |x+2| happens at x - 3 = -(x + 2) Rightarrow 2x = 1 Rightarrow x = 0.5. - For x le 0.5, |x+2| le |x-3| Rightarrow min = |x+2|. - For x > 0.5, |x-3| le |x+2| Rightarrow min = |x-3|.
Min function intersection graph for Q68 - JEE Main 2025 Evening
Min function intersection graph for Q68 - JEE Main 2025 Evening
### Step 1: Check Interval x le -2 Here, |x+2| = -(x+2) = -x-2: x^2 + 3x + 2 = -x - 2 Rightarrow x^2 + 4x + 4 = 0 (x+2)^2 = 0 Rightarrow x = -2 This is a valid solution as it lies precisely within the interval condition boundary. ### Step 2: Check Interval -2 < x le 0.5 Here, |x+2| = x+2: x^2 + 3x + 2 = x + 2 Rightarrow x^2 + 2x = 0 x(x+2) = 0 Rightarrow x = 0 quad textor quad x = -2 Only x = 0 fits inside this interval. ### Step 3: Check Interval x > 0.5 Here, min = |x-3| = 3-x: x^2 + 3x + 2 = 3 - x Rightarrow x^2 + 4x - 1 = 0 x = frac-4 pm sqrt16 - 4(1)(-1)2 = -2 pm sqrt5 Evaluating values: -2 + sqrt5 approx 0.236, which does not satisfy x > 0.5. Thus, no real roots occur in this span. Combining valid points, we find exactly 2 distinct real solutions (x = -2, 0). ### Pattern Recognition Sketching a rough visualization showing the parabola crossing below the sharp wedge of the combined absolute values makes it visually clear that there are exactly two crossing points, confirming the algebraic count. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Quadratic Equations Class 12 Mathematics: Limits, Continuity and Differentiability
Q57 jee_main_2025_24_jan_morning Limits of Algebraic and Trigonometric Functions
lim_x to 0 csc x left(sqrt2cos^2 x + 3cos x - sqrtcos^2 x + sin x + 4right) is equal to :
  • A. 0
  • B. frac12sqrt5
  • C. frac1sqrt15
  • D. -frac12sqrt5

Solution

### Related Formula To evaluate limits of indeterminate types containing radical forms, rationalize the numerator directly by multiplying by its conjugate element matching: (sqrtA - sqrtB)(sqrtA + sqrtB) = A - B ### Core Logic Rewrite the expression as a fraction with sin x in the denominator and rationalize the numerator: lim_x to 0 frac(2cos^2 x + 3cos x) - (cos^2 x + sin x + 4)sin x cdot left(sqrt2cos^2 x + 3cos x + sqrtcos^2 x + sin x + 4right) = lim_x to 0 fraccos^2 x + 3cos x - sin x - 4sin x cdot left(sqrt2cos^2 x + 3cos x + sqrtcos^2 x + sin x + 4right) ### Step 1: Simplify Numerator and Group Terms Express the numerator terms to isolate algebraic patterns: cos^2 x + 3cos x - 4 - sin x = (cos x - 1)(cos x + 4) - sin x Substitute this back into our rationalized limit format: = lim_x to 0 frac(cos x - 1)(cos x + 4) - sin xsin x cdot left(sqrt2cos^2 x + 3cos x + sqrtcos^2 x + sin x + 4right) ### Step 2: Distribute sin x in Denominator Split the limit across the two separated numerator expressions: = lim_x to 0 left[ fraccos x - 1sin x cdot (cos x + 4) - 1 right] cdot frac1sqrt2(1)+3 + sqrt1+0+4 Evaluate the limit component values: lim_x to 0 fraccos x - 1sin x = lim_x to 0 frac-2sin^2(x/2)2sin(x/2)cos(x/2) = lim_x to 0 [-tan(x/2)] = 0 Substituting this zero value simplifies the numerator expression directly: = left[ 0 cdot (1 + 4) - 1 right] cdot frac1sqrt5 + sqrt5 = frac-12sqrt5 ### Pattern Recognition Recognizing that fraccos x - 1sin x to 0 as x to 0 isolates the non-vanishing trigonometric components without needing full multi-stage application of L'Hôpital's rule. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Limits and Derivatives
Q72 jee_main_2025_28_jan_evening Limits of Trigonometric Functions
Let f(x)=lim_nrightarrow inftysum_r=0^nleft(fractan(x/2^r+1)+tan^3(x/2^r+1)1-tan^2(x/2^r+1)right). Then lim_xrightarrow0frace^x-e^f(x)(x-f(x)) is equal to
Numerical Answer. Answer: 1 to 1

Solution

### Related Formula Trigonometric identity: fractantheta + tan^3theta1-tan^2theta = tantheta left( frac1+tan^2theta1-tan^2theta right) = fractanthetacos 2theta Also note standard telescopic identity: tan 2phi - tanphi = fractanphicos 2phi ### Core Logic Let theta = fracx2^r+1. The term inside the summation simplifies to: tanleft(fracx2^rright) - tanleft(fracx2^r+1right) Now, evaluating the summation: sum_r=0^n left[ tanleft(fracx2^rright) - tanleft(fracx2^r+1right) right] = tan x - tanleft(fracx2^n+1right) Taking the limit as n to infty, tanleft(fracx2^n+1right) to tan(0) = 0. Therefore, f(x) = tan x. ### Step 1: Evaluate the Limit We need to find: lim_xrightarrow0frace^x-e^tan xx-tan x Factor out e^tan x from the numerator: lim_xrightarrow0 e^tan x cdot left[ frace^x-tan x - 1x-tan x right] Let u = x - tan x. As x to 0, u to 0. The limit becomes: lim_urightarrow0 e^0 cdot left[ frace^u - 1u right] = 1 times 1 = 1 ### Pattern Recognition Standard limit substitution lim_y to 0 frace^y - 1y = 1 applies cleanly whenever the argument in the exponent matches the entire denominator layout. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Trigonometry Class 12 Mathematics: Limits, Continuity and Differentiability
Q jee_main_2025_29_jan_morning Limits of Special Series
The value of lim_nto inftyleft(sum_K = 1^nfrack^3 + 6k^2 + 11k + 5(k + 3)!right) is:
  • A. frac43
  • B. 2
  • C. frac73
  • D. frac53

Solution

### Related Formula sum_k=1^infty left( frac1k! - frac1(k+3)! right) implies textTelescoping Series simplification ### Core Logic Rewrite the numerator polynomial to establish factor terms matching the factorial expansion base (k+3): k^3 + 6k^2 + 11k + 5 = (k^3 + 6k^2 + 11k + 6) - 1 = (k+1)(k+2)(k+3) - 1 ### Step 1: Simplify General Term T_k = frac(k+1)(k+2)(k+3)(k+3)! - frac1(k+3)! T_k = frac1k! - frac1(k+3)! This creates a clean telescoping layout format structure. ### Step 2: Sum the Series Writing out expanded \partial sums up to infinity: S = left( frac11! + frac12! + frac13! + frac14! + dots right) - left( frac14! + frac15! + frac16! + dots right) All higher terms cancel out systematically, leaving exactly the leading remaining fragments: S = frac11! + frac12! + frac13! = 1 + frac12 + frac16 = frac106 = frac53 ### Pattern Recognition Whenever factorials dominate fraction denominators, manipulate structural terms to align components via Telescoping sums (V_n - V_n-k). ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Limits, Continuity and Differentiability Class 11 Mathematics: Sequences and Series
Q73 jee_main_2025_29_jan_morning Sandwich Theorem and Greatest Integer Function
Let [t] be the greatest integer less than or equal to t. Then the least value of mathbfp in mathbbN for which lim_mathrmx to 0^+ left( mathrmx left( left[ frac1mathrmx right] + left[ frac2mathrmx right] + dots + left[ fracmathrmpmathrmx right] right) - mathrmx^2 left( left[ frac1mathrmx^2 right] + left[ frac2^2mathrmx^2 right] + dots + left[ frac9^2mathrmx^2 right] right) right) geq 1 is equal to
Numerical Answer. Answer: 24

Solution

### Related Formula lim_x to 0^+ x left[ frackx right] = k sum_k=1^n k = fracn(n+1)2, quad sum_k=1^n k^2 = fracn(n+1)(2n+1)6 ### Core Logic Using properties of Greatest Integer Function limits, as x to 0^+, fraction values diverge cleanly to continuous variable distributions: lim_x to 0^+ x left[ frackx right] = k implies sum_k=1^p k = fracp(p+1)2 Similarly, for the second block component part: lim_x to 0^+ x^2 left[ frack^2x^2 right] = k^2 implies sum_k=1^9 k^2 = frac9 times 10 times 196 = 285 ### Step 1: Setup Inequality Formulation Combine evaluated limits component parts: fracp(p+1)2 - 285 geq 1 fracp(p+1)2 geq 286 implies p(p+1) geq 572 ### Step 2: Solve for least natural number Evaluate product bounds of adjacent integers: If p = 23 implies 23 times 24 = 552 (False) If p = 24 implies 24 times 25 = 600 (True) Therefore, the least natural value of p is 24. ### Pattern Recognition Greatest Integer fractions simplify directly to standard scalar values inside limits evaluated at infinity or zero, letting you drop brackets and treat them as arithmetic sequences. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Mathematics: Limits

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