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mojhsa [17]
2 years ago
9

If cosa=1/2(a+1/a), verify that. cos2a=1/2(a²+1/a²)​

Mathematics
1 answer:
Alborosie2 years ago
3 0

Answer:

see explanation

Step-by-step explanation:

using the identity

cos2a = 2cos²a - 1 , then

cos2a

= 2[ \frac{1}{2}(a  + \frac{1}{a}) ]² - 1

= 2 [ \frac{1}{4} (a² + \frac{1}{a^2} + 2) ] - 1

= \frac{1}{2} (a² + \frac{1}{a^2} ) + 1 - 1

= \frac{1}{2} (a² + \frac{1}{a^2} ) ← thus verified

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Lindsay needs to interview a minimum of 15 people for a project in her
VARVARA [1.3K]

The required inequality is p≥9

Step-by-step explanation:

Given condition:

Lindsay needs to interview a minimum of 15 people.

Lindsay completed interviewing 6 people.

To Find:

The possible number of people she still needs to interview to complete her project.

Solution:

Let p be the number of people needed to complete the project.

To complete the project Lindsay needs to interview minimum 15 people.

                                            i.e.p≥ 15

But she has already interviewed 6 people. so, (15-6) = 9

                                            i.e p+6≥15

                                           or, p+6≥15

                                            ∴ p≥9

Hence the inequality that shows the people she still needs to  interview to complete the project is p≥9.

3 0
3 years ago
Which term is a term in this expression -3x- 7(x+4)
Over [174]

Answer:

A. -3x  

Step-by-step explanation:

Terms are the parts of an expression that are separated by + or - signs

-3x is a term, because it is separated from the rest of the expression by a - sign.

3 0
3 years ago
*BRIANLIEST WILL BE GIVEN*(08.06 LC)
Ganezh [65]
Adding the equations to eliminate p would be the correct step because when you add the equations together, the variable p would cancel out and be eliminated leaving you with 2w=35 you can then solve for the value of w which you can then input to find the value of p, allowing you to solve for the values of both p and w.
6 0
3 years ago
A line passes through (6,3), (8,4), and (n,-2). Find the value of n.
Ganezh [65]

Answer: n=2

Step-by-step explanation:

Get graph paper make a graph mark them on your graph and since it says (n,-2) its going down because of the negative 2 i don't think this helped but if it did

7 0
3 years ago
What is the volume of the right rectangular prism?
ddd [48]

Answer:

i think its 735

Step-by-step explanation:

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5 0
3 years ago
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