ANSWER
EXPLANATION
From the graph, the coordinates of Y are:
We want to find the image of this point after a dilation by a scale factor of -½ about the origin.
The rule for the dilation is :
To find the coordinates of Y', we plug the coordinates of Y.
The first choice is correct.
90 degrees should be right
Answer:
A. 3
Step-by-step explanation:
ΔDEC is bigger than ΔABC by 5. For the hypotenuse, 25 is 5 times bigger than 5.
So, side DE on ΔDEC has to be 5 times bigger than side AB on ΔABC.
If side AB equals 3, side DE equals 18 - 3, which is 15.
15 is five times bigger than 3, so the answer is A. 3.
Hope that helps.
I'm going to assume that the ' 7.51 ' is the angle expressed in radians.
So this is just like any other unit conversion exercise.
You know that 180 degrees = pi radians.
Divide each side by pi radians, and you have
180 degrees / pi radians = 1 .
Great ! Now take the angle you have ... 7.51 radians ...
and multiply it by ' 1 '.
(7.51 radians) x (180 degrees / pi radians) =
<em> </em> (7.51 x 180 / pi) degrees =<em> 430.29 degrees</em>
As you ( I ) worked through this problem, a very useful number
fell out . . . It's 180/pi = 57.296 , or just <em>57.3</em> is close enough.
Here's how you can use that number:
-- 1 radian = <u>57.3</u> degrees
-- 1 degree = 1/57.3 of a radian
-- Got some radians ? Multiply by <u>57.3</u> to get degrees.
-- Got some degrees ? Divide by <u>57.3</u> to get radians.
