The mathematical expression being evaluated is 1-2cos^2 25/1-2sin^2 65.
To solve this expression, you can apply the trigonometric identities:cos^2 x + sin^2 x = 1 and cos2x = 1 - 2sin^2 x
to rewrite the expression as:1 - 2(1 - 2sin^2 25)/1 - 2sin^2 65 = 1 - 2 + 4sin^2 25/1 - 2sin^2 65 = -1 + 4sin^2 25/1 - 2sin^2 65
Yes, the expression can be simplified further by using the double angle identity:sin2x = 2sinx cosx
Applying this identity to sin^2 25 and sin^2 65, the expression can be written as:= -1 + 4(1/2)cos 50/1 - 2(1/2)cos 130 = -1 + 2cos 50/1 - cos 130
After simplifying, the final answer to this expression is -1 + 2cos 50/1 - cos 130.
Yes, this expression can be evaluated numerically by substituting the values of cos 50 and cos 130 into the expression. The final numerical value will depend on the precision of the calculations and the units used for angle measurements.