Question

Question #757d3

Answer 1

1

Explanation:

use the rig identity using tangent and secant

`tan^2x+1=sec^2x`

`=>tan^2x=sec^2x-1`

`:.sec^2((3pi)/4)-1=tan^2((3pi)/4)`

`tan^2((3pi)/4)=[tan((3pi)/4)]^2=[-1]^2`

`=1`

Answer 2

1

Explanation:

Trig table of special arc gives:
`cos ((3pi)/4) = - sqrt2/2`
`sec ((3pi)/4) = 1/(cos) = - 2/sqrt2 = - sqrt2`
`sec^2 ((3pi)/4) = 2`
`sec^2 ((3pi)/4) - 1 = 2 - 1 = 1`