Question

The solution to the equation sin (1/5 cos^–1 x) = 1 is

• A. $\frac { \pi } { 3 }$
• B. $\frac { \pi } { 6 }$
• C. $\frac { \pi } { 4 }$
• D. No solution

Answer 1

Answer: (D)

No solution

Answer 2

Let $\frac { 1 } { 5 }$ cos^–1 x = a As 0 £ cos^–1 x £ p

so 0 £ 5a £ p Ž 0 £ a £ $\frac { \pi } { 5 }$

For this a, sin a can not be equal to 1.

So no solution.