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

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

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

3 years ago

A graph titled Cost of a Lunch in a School's Cafeteria has Days since school started on the x-axis and cost of lunch (dollars) o

Rufina [12.5K]

The true statement about the graph's slope is (c) Its slope is zero.

<h3>How to determine the true statement?</h3>

From the question, we have:

A horizontal line is at y = 2.5.

The horizontal line implies that the cost of lunch do not change

Horizontal lines have a slope of 0

Hence, the true statement about the graph's slope is (c) Its slope is zero.

Read more about slope at:

brainly.com/question/3493733

#SPJ1

8 0

1 year ago

Explain why vertical lines are a special case in the definition of parallel lines.

Nookie1986 [14]

Answer:

A vertical line has an infinite or undefined slope since the denominator is zero.

Step-by-step explanation:

Parallel lines by definition refers to lines that never intersect or meet since they have identical slopes. The slope of line is defined as;

(change in y)/(change in x)

For a vertical line, the y values are changing while the x values remain constant. The slope of this line will thus have a zero value in the denominator implying that its slope will not defined or will be infinity.

6 0

2 years ago

Read 2 more answers

In the process of electricity, what flow through

Natalija [7]

Current (A)

Q=It
where Q is electric charge, I is current and t is time

3 0

2 years ago