Question

SAT Question.

Can someone explain this really simple question to me.
Line t is tangent to the circle whose center is at (1,4). If the point of tangency is (0,0), what is the slope of line t?

What I did.

y2-y1/x2-x1
= 0-4/0-1
= 4

But the slope is -1/4.
Can someone explain. ><

Answer 1

yeah it doesn't work that way

Answer 2

im dumb.

Answer 3

draw your circle

Answer 4

just draw the circle, man

Answer 5

if the point of tangency is at (0,0) we can immediately tell the radius of the circle this is why there is no need to bother with graph and everything

Answer 6

You were close, just miss the final step.

You found the slope of the radius(the segment from the center the the point of tangency) which was 4

The tangent line t would be perpendicular to it. So it'll be the negative recipricol, or -1/4

Answer 7

idk

Answer 8

1. You know the center and you know a point on the circle.
2. Do you remember the relationship of a tangent at a point and the radius at that point?

I suggest you start by getting the formul for the line that includes the radius of the circle at the point of tangency.

Answer 9

downward slope = negative
wow great that's a huge clue

Answer 10

use socahtoa to solve for the angle
of the triangle and using the idea of perpendicular slope, m, being negative reciprocal will give you the slope of the line

Answer 11

that was the missing part you were told you were missing

Answer 12

good?

Answer 13

Yes thank you for your very thorough explanation! haha

Answer 14

yeahhhh no problem-o
I hope you're learning though
this is a question that checks if you can apply the parallel and perpendicular slopes you've learned

Answer 15

Yeah one of my weaker areas in the SAT is anything that has to do with slope since I didn't really pick it up in elementary and struggled from MS to HS. ><

Answer 16

http://www.ck12.org/student/
everything you need to know to pass

Answer 17

Oh my gosh, thank you!!! I'll be sure to check it out.