45.quad cos(40^(@)+theta)-sin(50^(@)-theta)+(cos^(2)40^(@)+cos^(2)50^(@))/(sin^(2)40^(@)+sin^(2)50^(@))

Without using trigonometric tables,evaluate each of the following: (sin^(2)20^(@)+sin^(2)70^(@))/(cos^(2)20^(0)+cos^(2)70^(@))+(sin(90^(@)-theta)sin theta)/(tan theta)+(cos(90^(@)-theta)cos theta)/(cot theta)+cos(40^(0)+theta)-sin(50^(@)-theta)+(cos^(2)40^(0)+cos^(2)50^(@))/(sin^(2)40^(0)+sin^(2)50^(@))

sin^(2)50^@+cos^(2)50^@=?

sin(50^(@)+theta)-cos(40^(@)-theta)

Evaluate: sin^(2)40^(@)-cos^(2)50^(@)

The value of {cos(40^(@)+theta)-sin(50^(@)-theta)} is

The value of cos(40^@+theta)-sin(50^@-theta) is

Prove that: (cos40^(@)+cos50^(@))/(sin40^(@)+sin50^(@))=1

Prove that: (cos40^(@)+cos50^(@))/(sin40^(@)+sin50^(@))=1

Solve cos(50^(@)+ theta) = sin (30^(@)+theta) .

4cos^(3)40^(@)-3sin50^(@)=