Is 1-cos(x)=(1-cos^2(x))/2 ?

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

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

prove 1-cos(x)=(1-cos^2(x))/2

prove

1 - cos (x) = \frac{1 - cos ^{2} ( x )}{2}

False

Solution steps

1 - cos (x) = \frac{1 - cos ^{2} ( x )}{2}

Show that the two sides are not equal

For

1 - cos (x) = \frac{1 - cos ^{2} ( x )}{2}

plug in

x = 1

1 - cos (1) = 0.45969 \dots

1 - cos (1)

Refine to a decimal form

= 0.45969 \dots

\frac{1 - cos ^{2} ( 1 )}{2} = 0.35403 \dots

\frac{1 - cos ^{2} ( 1 )}{2}

Refine to a decimal form

= 0.35403 \dots

The two sides are not equal

\Rightarrow False

\frac{1}{sin ^{2} ( x )} = 1 - tan^{2} (x)

(\frac{1}{2 cot ( x ) ( 1 - cos ^{2} ( x ) )}) = 2 cot (x)

3 sec^{2} (x) - 4 = 0

sin (3 θ) = 3 sin (θ) - 4 sin (3 θ)

(sec^{2} (x) cot (x)) + cot (x) = tan (x)

Is 1-cos(x)=(1-cos^2(x))/2 ?
The answer to whether 1-cos(x)=(1-cos^2(x))/2 is False