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3 years ago

Rewrite 1−2 sin ^2 (22.5∘) using a double-angle identity.

1 answer:

3 0

Using the identity :

Cos (2a) = 1-2 Sin^2(a)

Therefore :1−2 sin ^2 (22.5∘) = Cos(2a)
= Cos (2 * 22.5) = Cos 45

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<img src="https://tex.z-dn.net/?f=%5Csqrt%7B%28-81%29x%5E%7B2%7D%20%7D" id="TexFormula1" title="\sqrt{(-81)x^{2} }" alt="\sqrt{(

SSSSS [86.1K]

Answer:

We conclude that:

$\sqrt{\left(-81\right)x^2}=9ix$

Step-by-step explanation:

Given the radical expression

$\sqrt{\left(-81\right)x^2}$

simplifying the expression

$\sqrt{\left(-81\right)x^2}$

Remove parentheses: (-a) = -a

$\sqrt{\left(-81\right)x^2}=\sqrt{-81x^2}$

Apply radical rule: $\sqrt{-a}=\sqrt{-1}\sqrt{a},\:\quad \mathrm{\:assuming\:}a\ge 0$

$=\sqrt{-1}\sqrt{81x^2}$

Apply imaginary number rule: $\sqrt{-1}=i$

$=i\sqrt{81x^2}$

Apply radical rule: $\sqrt[n]{ab}=\sqrt[n]{a}\sqrt[n]{b},\:\quad \mathrm{\:assuming\:}a\ge 0,\:b\ge 0$

$=\sqrt{81}i\sqrt{x^2}$

$=9i\sqrt{x^2}$

Apply radical rule: $\sqrt[n]{a^n}=a,\:\quad \mathrm{\:assuming\:}a\ge 0$

$=9ix$

Therefore, we conclude that:

$\sqrt{\left(-81\right)x^2}=9ix$

7 0

3 years ago

Which expression represents the length of the spring after Gerard removes some weight? Gerard adds weight to the end of the hang

Andreyy89

Answer: p+(-q)

Step-by-step explanation:

4 0

2 years ago

Lian needs to solve the quadratic equation: x^2 - 4x - 2 = 0. Which statement about how Lian should solve this equation is true?

Ulleksa [173]

Answer:

x = 4.45 or x = - 4.45

Step-by-step explanation:

Here are the steps:

Substitute the values,

$4+\sqrt{-4^2-4(1*-2)}$ ÷ 2 × 1

x = 2 ± √6

x = 4.45 or x = - 4.45

good luck, i hope this helps :)

5 0

3 years ago

Read 2 more answers

What is the value of 56÷37? 56÷37?

Galina-37 [17]

Answer:

exact form is 56/37

decimal form is 1.513

mixed number form is 1 19/37

Step-by-step explanation:

8 0

2 years ago

Plzzz helpppppp nowwwww

snow_lady [41]

Answer:

x= 10

I hope i helped, best of luck!

4 0

2 years ago

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