body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

McGraw Hill Integrated II, 2012

MH

McGraw Hill Integrated II, 2012 View details

6. The Law of Sines and Law of Cosines

Continue to next subchapter

Exercise 71 Page 679

Use the Distance Formula.

sqrt(80) or approximately 8.9 units

Practice makes perfect

To determine the distance between two points, we use the Distance Formula. The coordinates of the given points are A(5,1) and C(-3,-3).

AC = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)

SubstitutePoints

Substitute ( 5,1) & ( -3,-3)

AC=sqrt(( -3- 5)^2+( -3- 1)^2)

Subtract terms

AC=sqrt((- 8)^2+(- 4)^2)

NegBaseToPosBase

(- a)^2=a^2

AC=sqrt(8^2+4^2)

Calculate power

AC=sqrt(64+16)

Add terms

AC=sqrt(80)

Use a calculator

AC=8.944271...

Round to 1 decimal place(s)

AC≈8.9

The distance between A and C is sqrt(80) or approximately 8.9 units.

Subchapter links

Exercises p.674-679