$A+B=90^o\to B=90^o-A\\\\\cos B=\cos(90^o-A)=\cos90^o\cos A+\sin90^o\sin A\\\\=\cos A+1\cdot\dfrac{3}{5}=0+\dfrac{3}{5}=\dfrac{3}{5}\\\\\boxed{\cos B=\dfrac{3}{5}}$

$Used:\\\\\cos(x+y)=\cos x\cos y+\sin x\sin y\\\\\cos90^o=0,\ sin90^o=1$

Other method:

Look at the picture.

$\sin\theta=\dfrac{opposite}{hypotenuse}\\\\\sin A=\dfrac{3}{5}\to opposite=3\ and\ hypotenuse=5$

$\cos\theta=\dfrac{adjacent}{hypotenuse}\\\\adjacent=3\ and\ hypotenuse=5\to\cos B=\dfrac{3}{5}$

8 0

2 years ago

Can you guys please help me. i don’t need the explanation i just need the answer

Fittoniya [83]

Answer:

Step-by-step explanation:

AOB + BOC = AOC

AOC = 90 since the lines are perpendicular

6x-12 + 3x+30 = 90

Combine like terms

9x + 18 = 90

Subtract 18 from each side

9x+18-18 = 90-18

9x = 72

divide by 9

9x/9 = 72/9

x = 8

AOB = 6x - 12

= 6*8 - 12

= 48 -12

= 36

5 0

2 years ago

Read 2 more answers

Find the volume of the cone.

Nesterboy [21]

V=πr2h

3=π·22·9

3≈37.69911

4 0

2 years ago

Read 2 more answers

You are cutting the small square patches to use to make a quilt . The size of the quilt is 60 inches by 72 inches . Find all the

kodGreya [7K]

Answer:

Step-by-step explanation:

one piece is 60×60 inch

5 pieces each measuring 12×12

so total 6 patches on one side and 6 pieces back side of same dimension.

5 0

2 years ago