$\displaystyle\int_0^{\pi/4} \tan x\,dx$ equals
A$\log 2$
B$\dfrac{1}{2}\log 2$
C$-\dfrac{1}{2}\log 2$
D$\log 3$
Answer & Solution
Correct answer: B. $\dfrac{1}{2}\log 2$
1. Antiderivative: $\int \tan x\,dx=\log|\sec x|$.
2. Evaluate: $\log\sec\tfrac{\pi}{4}-\log\sec 0=\log\sqrt{2}-\log 1$.
3. $\log\sqrt{2}=\tfrac12\log 2$.
4. Option A drops the $\tfrac12$; the value is $\dfrac{1}{2}\log 2$.
_Source: NCERT Class 12 Mathematics Ch 7 "Integrals", p.336_
Related questions
A rule counting sign changes to bound the number of positive real zeros belongs to:A single point where a rational graph is undefined, shown by an open circle, is a hole or A horizontal line that a graph approaches as inputs grow without bound is a horizontal:A vertical line that a graph rushes towards but never crosses is a vertical:A polynomial with real coefficients has 2 plus 3i as a zero, so it must also have as a zerFor a rational zero, numerators come from factors of the constant term and denominators frA polynomial takes a negative value at 3 and a positive value at 4, so between them it musA graph crosses straight through the x-axis at a zero. That zero has multiplicity that is: