Question

Sin400° = _____

-sin40°
sin40°
sin(-40)°

Answer 1

Sin 400° = Sin 40°

Explanation:

We have to find the value of the trigonometric function Sin 400°

Here,

Sin 400° = Sin (360° + 40°)

The picture shown below shows that in 1st quadrant All trigonometric functions( Sin, Cos, Tan, Cosec, Sec, Cot ) are positive.

And Sin(360° + Ф°) = Sin ( Ф°)

= Sin ( 40°)

Therefore, Sin 400° = Sin 40°