Question

could someone please check my last math question ?

Answer 1

Whats the question?

Answer 2

The curve y = ax2 + bx + c touches the line y = x in the origin. It also touches the line y = 2x +3. Determine the function

Answer 3

the curve is y=ax^2... not 2ax

Answer 4

Ive completely forgotten how to find tangent lines... sorry.
I'll look around and see if I can remember how to do these.

Answer 5

\[y=ax^2+bx+c\quad,\quad y'=2ax+b\]\[y(x=0)=c=0\quad,\quad y'(x=0)=b=x'=1\]\[ax^2+x=2x+3\quad,\quad ax^2-x-3=0\quad,\quad D=(-1)^2-4a(-3)=1+12a=0\quad,\quad a=-\frac{1}{12}\]\[y=-\frac{1}{12}x^2+x\]

Answer 6

what is D ?

Answer 7

i mean why is D=1