Question

If Cos 26= m, Determine in terms of m: 2 Sin 277​

Answer 1

m+1

Explanation:

Using the double angle formula, you can do

cos26 = cos^2*13-sin^3*13

cos^2*13 - (1-cos^2*13)

2cos^2*13 = cos^2*b+1

= m+1

Because 13 degrees + 77 degrees = right angle,

using property of trigonometric functions, cos13=sin77

= m+1