Is cos(2x)=-2sin(x^2)+1 ?

The answer to whether cos(2x)=-2sin(x^2)+1 is False

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prove cos(2x)=-2sin(x^2)+1

prove

cos (2 x) = - 2 sin (x^{2}) + 1

False

Solution steps

cos (2 x) = - 2 sin (x^{2}) + 1

Show that the two sides are not equal

For

cos (2 x) = - 2 sin (x^{2}) + 1

plug in

x = 1

cos (2 \cdot 1) = - 0.41614 \dots

cos (2 \cdot 1)

Refine to a decimal form

= - 0.41614 \dots

- 2 sin (1^{2}) + 1 = - 0.68294 \dots

- 2 sin (1^{2}) + 1

Refine to a decimal form

= - 0.68294 \dots

The two sides are not equal

\Rightarrow False

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p ro v e sin (x) = sin (x + 2 π)

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