trigonometry question? how does 1-cos^2 theta equal sin^2?
- PolyhymnioLv 73 years ago
By the Pythagorean theorem. It is simple geometry
- KrishnamurthyLv 73 years ago
Since sin^2 (θ) + cos^2(θ) = 1
1 - cos^2 (θ)
= sin^2 (θ)
- Mike GLv 73 years ago
Right triangle with legs x and y with hypotenuse h
x^2+y^2 = h^2
(x/h)^2+(y/h)^2 = 1
cos^2(θ)+sin2(θ) = 1
sin^2(θ = 1-cos^2(θ)
- oldschoolLv 73 years ago
Values for sine and cosine come from the "unit circle" or a circle with radius = 1. The sine and cosine values are the projections of that radius on the vertical (sine) and horizontal (cosine) axis for angles 0 - 360°. In other words a right triangle with hypotenuse = 1.
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- phuongLv 53 years ago
From the equation : sin^2 ( theta ) + cos ^2( theta ) = 1