Quadratic and linear Intersection

[master_333]

Homework Statement

How many points of intersection does the line y = x have with the parabola y = 6x − x2 −10 ?
A) none
B) one
C) two
D) three
E) more than three

Homework Equations

The Attempt at a Solution

x = 6x - x^2 - 10
-x^2+5x - 10
Used b^2 - 4ac to check the number of intersections.

The answer I got is . However my teacher marked it as incorrect. I still cannot find the problem, please help. If my teacher marked it wrong, please tell me so because I think he did. Thanks.

 

[Dr. Courtney]

Graphing makes it clear.

 

[Rumplestiltskin]

The Attempt at a Solution

x = 6x - x^2 - 10
-x^2+5x - 10
Used b^2 - 4ac to check the number of intersections.

The answer I got is . However my teacher marked it as incorrect. I still cannot find the problem, please help. If my teacher marked it wrong, please tell me so because I think he did. Thanks.

What was your answer? What did you plug in for b² - 4ac? Your approach is correct, but I'd draw a graph to be sure. (Hint: you know the parabola is negative, and you know the y-intercept is -10.)

 

[Mark44]

Homework Statement

How many points of intersection does the line y = x have with the parabola y = 6x − x2 −10 ?
A) none
B) one
C) two
D) three
E) more than three

Homework Equations

The Attempt at a Solution

x = 6x - x^2 - 10
-x^2+5x - 10

Where did the = go? You have it two lines above, but not in the line above here.

Used b^2 - 4ac to check the number of intersections.

The answer I got is .

Is what?

However my teacher marked it as incorrect.

Your teacher marked what as incorrect?
You need to give us enough information so that we can provide meaningful help.

I still cannot find the problem, please help. If my teacher marked it wrong, please tell me so because I think he did. Thanks.

 

[master_333]

Sorry I know the right answer now. However I typed it in wrong. I forgot to write that the answer i got is A . Thanks

 

[haruspex]

Sorry I know the right answer now. However I typed it in wrong. I forgot to write that the answer i got is A . Thanks

Are you saying that your teacher's answer is not A, or that you typed the question wrongly (or both)?