Question

Find the exact value of each expression.
sin75°
cos(-75°)

Answer 1

sin(75)

=0.96

cos(-75)

=0.25

Answer 2

Explanation:

sin 75°

sin(30°+45°)

sin30°*cos45°+cos30°sin45°

1/2*1/
`√(2)` +
`√(3)`/2*1
`\sqrt{2`

1/2
`√(2)`+
`√(3)`/2
`√(2)`

1+3/2
`√(2)`

cos(-75°)

-cos(180°-105°)

-cos(-105°)

cos 105°

cos(45°+60°)

cos45°cos60°-sin45°sin60°

1/
`√(2)` *1/2-1/
`√(2)` *
`√(3)` /2

1/2
`\sqrt{2`-
`\sqrt{3`/2
`√(2)`

1-
`√(3)`/2
`√(2)`