Prove the identity with steps.

Mathematics

1 answer:

Sav [38]2 years ago

4 0

Remember that a double angle formula for cosine is
$\cos(2x)=\cos^{2}x-\sin^{2}x$

So
$\cos^{2}(2x)-\sin^{2}(2x)=\cos(4x)$
$\rightarrow \cos^{2}(2x)-\sin^{2}(2x)=\cos(2*2x)$
$\rightarrow \cos^{2}(2x)-\sin^{2}(2x)=\cos^{2}(2x)-\sin^{2}(2x)$

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1-116 1.2.6

ankoles [38]

Answer:

A. 30 adults; B. 24 not dolls

Step-by-step explanation:

$\begin{array}{rcl}\text{No. of adults} & = & \text{No. of visitors} \times \text{Fraction who are adults}\\& = & \text{100 visitors} \times \dfrac{\text{3 adults}}{\text{10 visitors}} \\& = & \textbf{30 adults}\\\end{array}$

If five-eighths of the prizes were dolls, then three-eighths of the prizes were not dolls.

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