If sin 20 degree=a and cos20 degree=b then which of the following represents the correct value of sin 70 degree in terms of a and/or b?
1) a+b
2) a
3) b
4)a-b

Respuesta :

ANSWER

3) b

EXPLANATION

Given that:

[tex] \sin(20 \degree) = a[/tex]

and

[tex] \cos(20 \degree) = b[/tex]

Recall that the sine and cosine functions are equal for complementary angles.

This implies that,

[tex] \sin(70 \degree) = \cos(20 \degree) [/tex]

[tex] \sin(70 \degree) = b[/tex]