Question

write the value of sin 225 degree

Answer 1

Put the value of sin

Answer 2

Answer:

$-\frac{1}{\sqrt2}$

Step-by-step explanation:

We have to find the value of sin225°

We can write the angle 225 degrees as

225° = (180+45)°

Thus, we have

sin(180+45)°

(180+45)° must be in 3rd quadrant and we know that in third quadrant sine is negative. Hence, we have

$\sin(180+\theta)=-\sin\theta$

Thus, the expression becomes

$sin(180+45)^{\circ}\\= -sin45^{\circ}\\\\-\frac{1}{\sqrt2}$