Hello Paymemoney Originally Posted by
Paymemoney Hi
Need help on the following question:
1) A straight line with gradient 2 passes through the vertex of the parabola $\displaystyle y= x^2-5x+3$. What is the equation to the line?
P.S
I don't know what method you use for finding the vertex of a parabola, but you can complete the square:$\displaystyle y= x^2-5x+3$$\displaystyle =\left(x-\frac52\right)^2 -\frac{25}{4}+3$
$\displaystyle =(x-2.5)^2 -3.25$
So the vertex is at $\displaystyle (2.5, -3.25)$. Now use
$\displaystyle y -y_1 = m(x-x_1)$
to find the equation of the line.
Can you complete it now?
Grandad