Question

What is the value of cos15 cos45 - sin15 sin45

please help me!

Answer 1

(solving sin)

= sin15 sin45

= (√6 - √2)/4 * (√2) / 2

= (-1 + √3) / 4

(Subtracting both)

= (1 + √3) / 4 - (-1 + √3) / 4

= 1/2

Explanation:

Answer 2

1/2

Explanation:

(Solving cos first)

= cos15 cos 45

= (√6 + √2)/4 * (√2) / 2

= (1 + √3) / 4

(solving sin)

= sin15 sin45

= (√6 - √2)/4 * (√2) / 2

= (-1 + √3) / 4

(Subtracting both)

= (1 + √3) / 4 - (-1 + √3) / 4

= 1/2

I hope my answer helps you.