2 years ago

Simplify [2 (cos 210 + i sin 210)]^2

1 answer:

4 0

2{(cos^210+isin^210)}^2

2(cos^210-sin^10+2i*cos10*sin10)

2(cos20+i*sin20)

cos^2Ф-sin^2Ф=cos2Ф and 2sinФcosФ=sin2Ф here Ф=10°

You might be interested in

Andreas93 [3]

Answer: $\frac{7}{120}$

Step-by-step explanation:

8 0

2 years ago

Umnica [9.8K]

Range is 1 because they all go up by 1

8 0

2 years ago

Eva8 [605]

Answer:

hi I was wondering if I could come in

3 0

3 years ago

jolli1 [7]

The sum of four and a number

7 0

3 years ago

kotykmax [81]

Answer:

$cos(C) =\frac{40}{41}\\\\cos(C)=0.976$

Step-by-step explanation:

To find the $cos (C)$ we must use the cosine theorem.

The cosine theorem says that:

$c^2 = a^2 +b^2 -2abcos(C)$

In this case:

$c=AB = 9$

$b=CA = 41$

$a=BC = 40$

$9^2 = 40^2 +41^2 -2(40)*(41)cos(C)$

$9^2- 40^2- 41^2 =-2(40)*(41)cos(C)$

$cos(C) = -\frac{9^2- 40^2- 41^2}{2(40)*(41)}$

$cos(C) =\frac{40}{41}\\\\cos(C)=0.976$

7 0

3 years ago