SOLUTION: How do you prove
sin(90-x)=cosx
Thankyou!
Algebra.Com
Question 734584: How do you prove
sin(90-x)=cosx
Thankyou!
Answer by MathLover1(20849) (Show Source): You can put this solution on YOUR website!
Both functions are trigonometric cofunctions of each other, in that function of the complementary angle, which is the "cofunction," is equal to the other function:
and
If you draw a diagram, it's obvious.
Draw a right triangle.
Let one of the acute angles be .
Then the other acute angle must be , since the sum of the degrees in the triangle must be .
By definition of and ,
.
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