$\displaystyle\int_0^\pi \sin x\, dx = ?$
A$0$
B$1$
C$2$
D$\pi$
Answer & Solution
Correct answer: C. $2$
$[-\cos x]_0^\pi = -\cos\pi + \cos 0 = 1 + 1 = 2$.
Related questions
$\displaystyle\int_0^{\infty} \dfrac{\ln x}{1 + x^2}\, dx = ?$$\displaystyle\int_0^1 \dfrac{x - 1}{\ln x}\, dx = ?$ (Frullani-type)Given $\displaystyle\int_0^{\pi/2} \dfrac{ in^n x}{ in^n x + \cos^n x}\, dx$, the value isIf $\displaystyle f(x) = \int_0^x t in t\, dt$, then $f''(\pi) = ?$$\displaystyle\int_0^{\pi/2} \dfrac{dx}{1 + \tan^3 x} = ?$Evaluate $\displaystyle\lim_{n\to\infty} \dfrac{1^k + 2^k + \cdots + n^k}{n^{k+1}}$ for $k$\displaystyle\int_0^\pi \dfrac{x}{1 + in x}\, dx = ?$$\displaystyle\int_0^{\pi/4} \tan^4 x\, dx = ?$