HELP ASAP!!!!! i wasted 30 points because i asked this question 3 times with no answer please.

Subtracting/adding mixed fractions

pishuonlain [190]

A)
= 3 2/4
= 3 1/2

b)
= 7 10/15 + 2 3/15
= 9 13/15

4 0

2 years ago

Cos^2x+cos^2(120°+x)+cos^2(120°-x) i need this asap. pls help me

o-na [289]

Answer:

$\frac{3}{2}$

Step-by-step explanation:

Using the addition formulae for cosine

cos(x ± y) = cosxcosy ∓ sinxsiny

---------------------------------------------------------------

cos(120 + x) = cos120cosx - sin120sinx

= - cos60cosx - sin60sinx

= - $\frac{1}{2}$ cosx - $\frac{\sqrt{3} }{2}$ sinx

squaring to obtain cos² (120 + x)

= $\frac{1}{4}$ cos²x + $\frac{\sqrt{3} }{2}$ sinxcosx + $\frac{3}{4}$ sin²x

--------------------------------------------------------------------

cos(120 - x) = cos120cosx + sin120sinx

= -cos60cosx + sin60sinx

= - $\frac{1}{2}$ cosx + $\frac{\sqrt{3} }{2}$ sinx

squaring to obtain cos²(120 - x)

= $\frac{1}{4}$ cos²x - $\frac{\sqrt{3} }{2}$ sinxcosx + $\frac{3}{4}$ sin²x

--------------------------------------------------------------------------

Putting it all together

cos²x + $\frac{1}{4}$ cos²x + $\frac{\sqrt{3} }{2}$ sinxcosx + $\frac{3}{4}$ sin²x + $\frac{1}{4}$ cos²x - $\frac{\sqrt{3} }{2}$ sinxcosx + $\frac{3}{4}$ sin²x

= cos²x + $\frac{1}{2}$ cos²x + $\frac{3}{2}$ sin²x

= $\frac{3}{2}$ cos²x + $\frac{3}{2}$ sin²x

= $\frac{3}{2}$ (cos²x + sin²x) = $\frac{3}{2}$

5 0

2 years ago

Need help not quiz need help please and

Eva8 [605]

Answer:

b

Step-by-step explanation:

..................................

6 0

2 years ago

Triangle A B C is cut by line segment S T. Line segment S T goes from side A B to side C B. Lines S T and A C are parallel. The

maksim [4K]

Answer:

Option C.

Step-by-step explanation:

Given information: In triangle ABC, ST║AC, SB=10 ft, BT=9 ft and CT=2.7 ft.

Triangle proportionality theorem: If a line segment parallel to a side of a triangle then the line segments divides the remaining sides proportionally.

Using triangle proportionality theorem we get

$\dfrac{SA}{SB}=\dfrac{CT}{BT}$

$\dfrac{SA}{10}=\dfrac{2.7}{9}$

On cross multiplication we get

$9\times SA=2.7\times 10$

$9SA=27$

Divide both sides by 9.

$SA=3$

The length of SA is 3ft.

Therefore, the correct option is C.

8 0

2 years ago

Read 2 more answers

Describe an animal adaptation and explain how it helps survival.

marin [14]

Answer and Step-by-step explanation:

Animal adaption for Birds.

Birds who live on a tropical island with large, hard shell nuts.

The birds have small beaks, but over time, their beaks become bigger, stronger, and sharper, so that it can break into the hard shell nuts, allowing them to eat the nuts.

#teamtrees #WAP (Water And Plant)

3 0

2 years ago

HELP ASAP!!!!! i wasted 30 points because i asked this question 3 times with no answer please.​

HELP ASAP!!!!! i wasted 30 points because i asked this question 3 times with no answer please.