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4 years ago

Cos(3x) = cos^2x - 3sin^2x cosx

Mathematics

1 answer:

EleoNora [17]4 years ago

8 0

$\cos3x=\cos(2x+x)=\cos2x\cos x-\sin2x\sin x$
$=(\cos^2x-\sin^2x)\cos x-2\sin^2x\cos x$
$=\cos^3x-3\sin^2x\cos x$

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Licemer1 [7]

Answer:

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Step-by-step explanation:

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4 years ago

Read 2 more answers

Given the following constants for a standard form quadratic equation, determine the nature of its roots.

Firdavs [7]

Given that

a=3

b=3

c=2

The number and kind of roots depend on the Discriminant of the equation .

Formula for the Discriminant ,D is given by this

$D = b^{2} -4ac$

So using the formula we get that

$D = 3^{2} -4*3*2\\D=9-24\\D= -15$

Concept is that if the Discriminant is negative then no real solution is possible ,

here using the Discriminant formula we have got the Discriminat value as -15 which is a negative number so we say there is no real solution for the given information .

Hence C is the correct option .

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3 years ago

Given: 6g+4a=7a prove: g/a=1/2

Likurg_2 [28]

Answer:

Step-by-step explanation:

6g + 4a = 7a

⇔ 6g = 7a - 4a

⇔ 6g = 3a

Divide both side by 6a

⇒ $\frac{6g}{6a} = \frac{3a}{6a}$ ⇔ $\frac{g}{a} = \frac{1}{2}$

I hope this will help you.

3 0

3 years ago

True or False: As the value of cos(x) approaches 1 and the value of sin(x) approaches 0, the value of tan(x) approaches infinity

nevsk [136]

Answer: False

Step-by-step explanation:

We can write tan(x) = sin(x)/cos(x)

if cos(x) tends to 1, and sin (x) tends to 0 (this happens aronund the point x = 0)

then we have:

Tan(x) = 0/1 = 0

Then the statement is false, as cos(x) approaches 1 and sin(x) approaches 0, tan(x) also approaches 0.

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4 years ago

What is the simplified form of the expression 3²+7-y²-5-2y²-1

Montano1993 [528]

3² + 7 - y² - 5 - 2y² -1
= -3y² + 9 + 1 = -3y² + 10

3 0

3 years ago