Chapter 6 - Inverse Circular Functions and Trigonometric Equations - Section 6.4 Equations Involving Inverse Trigonometric Functions - 6.4 Exercises - Page 279: 1

C

(a) $arctan1=x$ $tanx=1$ or $tanx=tan45^{\circ}$ Thus, $x=45^{\circ}$ which is $\ne 0$ (b) $arccos0=x$ $cos x=0$ or $cosx=cos 90^{\circ}$ Thus, $x=90^{\circ}$ which is $\ne 0$ (c) $arcsin0=x$ $sinx=0$ or $sinx=sin0^{\circ}$ Thus, $x=0^{\circ}$ which is equal to $0$ Hence, the correct option is C.