Section A — MCQ (Single Correct)
Question 1
Evaluate the following algebraic rational fraction integral: $\int \frac{x^2 - 1}{x^4 + x^2 + 1} \, dx$.
A
$\frac{1}{2}\ln\left|\frac{x^2-x+1}{x^2+x+1}\right| + C$
B
$\frac{1}{2}\ln\left|\frac{x^2+x+1}{x^2-x+1}\right| + C$
C
$\tan^{-1}\left(\frac{x^2-1}{x}\right) + C$
D
$\frac{1}{2\sqrt{3}}\ln\left|\frac{x^2-\sqrt{3}x+1}{x^2+\sqrt{3}x+1}\right| + C$
Question 2
Solve the rational trigonometric fraction integral $\int \frac{1}{1 + 3\sin^2 x} \, dx$:
A
$\frac{1}{2}\tan^{-1}(2\tan x) + C$
B
$\tan^{-1}(2\tan x) + C$
C
$\frac{1}{2}\tan^{-1}(\tan x) + C$
D
$\frac{1}{4}\ln\left|\frac{\tan x - 2}{\tan x + 2}\right| + C$
Question 3
Evaluate the following algebraic integration form: $\int \frac{x^2}{(x\sin x + \cos x)^2} \, dx$.
A
$\frac{\sin x - x\cos x}{x\sin x + \cos x} + C$
B
$\frac{-\rm{sec} \, x}{x\sin x + \cos x} + C$
C
$\frac{\sin x + x\cos x}{x\sin x + \cos x} + C$
D
$\frac{x\sin x - \cos x}{x\sin x + \cos x} + C$
Question 4
The integral value for the Euler-algebraic substitution form $\int \frac{1}{x \sqrt{1 - x^5}} \, dx$ matches:
A
$\frac{1}{5}\ln\left|\frac{\sqrt{1-x^5}-1}{\sqrt{1-x^5}+1}\right| + C$
B
$-\frac{2}{5}\ln\left|1 + \sqrt{1-x^5}\right| + C$
C
$\frac{2}{5}\tanh^{-1}\left(\sqrt{1-x^5}\right) + C$
D
$-\frac{1}{5}\ln\left|\frac{1 + \sqrt{1-x^5}}{x^{5/2}}\right| + C$
Question 5
Solve the rational fraction containing a linear radical term: $\int \frac{1}{(x-1)\sqrt{x+2}} \, dx$.
A
$\frac{1}{\sqrt{3}}\ln\left|\frac{\sqrt{x+2}-\sqrt{3}}{\sqrt{x+2}+\sqrt{3}}\right| + C$
B
$\frac{1}{2\sqrt{3}}\ln\left|\frac{\sqrt{x+2}-\sqrt{3}}{\sqrt{x+2}+\sqrt{3}}\right| + C$
C
$\frac{2}{\sqrt{3}}\tan^{-1}\left(\sqrt{\frac{x+2}{3}}\right) + C$
D
$\ln\left|\frac{\sqrt{x+2}-1}{\sqrt{x+2}+1}\right| + C$
Question 6
Evaluate the specific algebraic substitution integral form $\int \frac{x^7}{(1-x^4)^2} \, dx$:
A
$\frac{1}{4}\left[ \ln|1-x^4| + \frac{1}{1-x^4} \right] + C$
B
$\frac{1}{4}\left[ \ln|1-x^4| - \frac{1}{1-x^4} \right] + C$
C
$\frac{1}{4(1-x^4)} + C$
D
$\ln|1-x^4| + \frac{x^4}{4(1-x^4)} + C$
Question 7
Find the value of the structural trigonometric product integral: $\int \frac{\cos 4x - 1}{\cot x - \tan x} \, dx$.
A
$-\frac{1}{4}\cos 4x + C$
B
$\frac{1}{8}\cos 4x + C$
C
$-\frac{1}{8}\cos 4x + C$
D
$\frac{1}{4}\sin 4x + C$
Question 8
Evaluate the symmetric algebraic transformation form $\int \frac{1}{x^4 + 1} \, dx$:
A
$\frac{1}{2\sqrt{2}}\tan^{-1}\left(\frac{x^2-1}{\sqrt{2}x}\right) + \frac{1}{4\sqrt{2}}\ln\left|\frac{x^2+\sqrt{2}x+1}{x^2-\sqrt{2}x+1}\right| + C$
B
$\frac{1}{2\sqrt{2}}\tan^{-1}\left(\frac{x^2-1}{\sqrt{2}x}\right) - \frac{1}{4\sqrt{2}}\ln\left|\frac{x^2+\sqrt{2}x+1}{x^2-\sqrt{2}x+1}\right| + C$
C
$\frac{1}{\sqrt{2}}\tan^{-1}\left(\frac{x^2-1}{\sqrt{2}x}\right) + C$
D
$\frac{1}{4\sqrt{2}}\ln\left|\frac{x^2+\sqrt{2}x+1}{x^2-\sqrt{2}x+1}\right| + C$
Question 9
Solve the following inverse trigonometric substitution integral: $\int \frac{\sin^{-1}\sqrt{x} - \cos^{-1}\sqrt{x}}{\sin^{-1}\sqrt{x} + \cos^{-1}\sqrt{x}} \, dx$.
A
$\frac{2}{\pi}\left[ (2x-1)\sin^{-1}\sqrt{x} + \sqrt{x-x^2} \right] - x + C$
B
$\frac{2}{\pi}\left[ x\sin^{-1}\sqrt{x} + \sqrt{x-x^2} \right] + C$
C
$\frac{4}{\pi}\sqrt{x-x^2} - x + C$
D
$(2x-1)\sin^{-1}\sqrt{x} + C$
Question 10
If $\int \frac{1}{x^3 + x^5} \, dx = \frac{A}{x^2} + B\ln|x| + C\ln|1+x^2| + V$, then the values of the constant coefficients are:
A
$A = -1/2, B = 1, C = -1/2$
B
$A = -1/2, B = -1, C = 1/2$
C
$A = 1/2, B = 1, C = -1/2$
D
$A = -1/2, B = 1, C = 1/2$
Section B — Integer Type
Question 11 — Integer answer
If the substitution integral satisfies $\int \frac{x^3}{\sqrt{1+x^2}} \, dx = \frac{1}{k}(1+x^2)^{3/2} - \sqrt{1+x^2} + C$, find the value of the integer denominator $k$.
Question 12 — Integer answer
Find the total number of distinct linear factors that appear in the denominator of the partial fraction decomposition for $R(x) = \frac{1}{x^4 - 5x^2 + 4}$.
Question 13 — Integer answer
If $\int e^x \left[ \frac{x-1}{x^2} \right] \, dx = \frac{e^x}{k \cdot x} + C$, find the value of the integer scalar parameter $k$.
Section C — Assertion & Reasoning
Question 14 — Assertion / Reason
Assertion (A): The algebraic substitution integral $\int \frac{1}{x^2 - a^2} \, dx$ can be evaluated by using the algebraic substitution $x = a\sin\theta$.
Reason (R): Trigonometric substitutions use standard identities to simplify quadratic radical fields like $\sqrt{a^2 - x^2}$ into single terms.
A
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is NOT the correct explanation of A
C
A is true but R is false
D
A is false but R is true
Solution: A is false (because $x = a.
Question 15 — Assertion / Reason
Assertion (A): To evaluate rational functions of the type $\int \frac{1}{a + b\cos x} \, dx$, using the Weierstrass half-angle transformation $t = \tan(x/2)$ is an effective method.
Reason (R): This substitution transforms trigonometric rational functions into standard algebraic fractions that can be solved using standard quadratic forms.
A
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is NOT the correct explanation of A
C
A is true but R is false
D
A is false but R is true
Solution: Both A and R are true, and R is the correct explanation.