Give expression: 7x -3 evaluate if x = 8

7x-3= 53

Step-by-step explanation:

x=8

7x8=56

56-3=53

Cos(π/2 - θ) = A

Step-by-step explanation:

We know that:

Sin(θ) = A

And we want to find the value of Cos(π/2 - θ)

Here we can use the cosine relationship:

Cos(a - b) = Cos(a)*Cos(b) + Sin(A)*Sin(B)

Then:

Cos(π/2 - θ) = Cos(π/2)*Cos(θ ) + Sin(π/2)*Sin(θ)

We know that:

Cos(π/2) = 0

Sin(π/2) = 1

Then:

Cos(π/2 - θ) = Cos(π/2)*Cos(θ ) + Sin(π/2)*Sin(θ) = 0*Cos(θ ) + 1*Sin(θ)

                    = 1*Sin(θ) = A

Cos(π/2 - θ) = A