Is cos(a-b)=cos(a)cos(b)+sin(a)sin(b) ?

The answer to whether cos(a-b)=cos(a)cos(b)+sin(a)sin(b) is True

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prove cos(a-b)=cos(a)cos(b)+sin(a)sin(b)

prove

cos (a - b) = cos (a) cos (b) + sin (a) sin (b)

True

Solution steps

cos (a - b) = cos (a) cos (b) + sin (a) sin (b)

Use the Angle Difference identity:

cos (s - t) = cos (s) cos (t) + sin (s) sin (t)

\Rightarrow True

1 + cos^{2} (x) csc^{2} (x) = \frac{1}{sin ^{2} ( x )}

sin (x) cos (x) = sin (2 x)

tan (x) + cot (x) = sec (x) cos (x)

tan^{2} (\frac{5 π}{4}) = tan (\frac{5 π}{4})

sin (\frac{π}{2} - θ) = sin (θ - \frac{π}{2})

Is cos(a-b)=cos(a)cos(b)+sin(a)sin(b) ?
The answer to whether cos(a-b)=cos(a)cos(b)+sin(a)sin(b) is True