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2 years ago

Make cos C the subject of the formula C?= a? + b? - 2ab cos C

Mathematics

1 answer:

lara31 [8.8K]2 years ago

5 0

<h3>Answer: Choice E</h3>

Work Shown:

$c^2 = a^2 + b^2 - 2ab\cos(C)\\\\c^2 + 2ab\cos(C) = a^2 + b^2\\\\2ab\cos(C) = a^2 + b^2 - c^2\\\\\boldsymbol{\cos(C) = \frac{a^2 + b^2 - c^2}{2ab}}\\\\$

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Can the sides of a triangle have lengths 3, 3, and 10?

Bingel [31]

Answer:

Step-by-step explanation:

According to the property of the triangle ,

sum of any two sides should we greater then third side of the triangle.

Here, Measurement of three sides are given as 3,3,5 .

So, sum of the measurement of first two sides is 6.

And third side equals 10.

Clearly 6 is less than 10. So . it violates the property sum of any two sides should we greater then third side of the triangle.

Thus , Sides of a triangle can't be 3,3,10.

8 0

3 years ago

Read 2 more answers

: A sports store sells a total of 70 soccer balls in one month, and collects a total of $2,400. A limited Edition soccer ball is

sweet-ann [11.9K]

Answer:

The store sold 43 pro NSL soccer balls.

The store sold 27 limited Edition soccer balls.

Step-by-step explanation:

Let x represent number of limited Edition soccer balls and y represent the number of pro NSL soccer balls.

We have been given that a sports store sells a total of 70 soccer balls in one month. We can represent this information in an equation as:

$x+y=70...(1)$

Cost of x limited Edition soccer balls: $65x$

Cost of y pro NSL soccer balls: $15x$

We are also told that store collected a total of $2,400. We can represent this information in an equation as:

$65x+15y=2400...(2)$

From equation (1), we will get:

$x=70-y$

Substituting this value in equation (2), we will get:

$65(70-y)+15y=2400$

$4550-65y+15y=2400$

$4550-50y=2400$

$4550-4550-50y=2400-4550$

$-50y=-2150$

$\frac{-50y}{-50}=\frac{-2150}{-50}$

$y=43$

Therefore, the store sold 43 pro NSL soccer balls.

Now, we will substitute $y=43$ in equation (1) to solve for x:

$x+43=70$

$x+43-43=70-43$

[tex]x=27/tex]

Therefore, the store sold 27 limited Edition soccer balls.

4 0

3 years ago

Solve by whatever method you would prefer. (Leave answers as improper fractions) 3x+2y=-10 2x-5y=3 (Show your work (Brainliest)

alexandr1967 [171]

Answer:

y = -29/19 and x = -44/19

Step-by-step explanation:

3x + 2y = -10 multiply by -2 ⇔ -6x - 4y = 20

2x - 5y = 3 multiply by 3 ⇔ <u> 6x - 15y = 9 </u>

Add the two equation -19y = 29

y = -29/19

Use equation one and solve for x

3x + 2(-29/19) = -10

3x - 58/19 = -10

3x = -10 + 58/19

3x = -190/19 + 58/19

3x = (-190 + 58)/19

3x = -132/19

x = - 132/ 19 ÷3 $\frac{-132}{19} (\frac{1}{3} ) = \frac{-44}{19}$

x = -44/19

5 0

2 years ago

What is the Y intercept of X +4=-7

antiseptic1488 [7]

Answer:

there is no y-intercept

3 0

3 years ago

Read 2 more answers

A square has a diagonal of 10 cm. What are the lengths of the sides?

Katen [24]

Answer:

5√2 cm

Step-by-step explanation:

Let x = the length of a side of the square

a2 + b2 = c2

x2 + x2 = 102

2x2 = 100

x2 = 50

x = √50

x = 5√2 cm

5 0

3 years ago