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

2. 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?

Hello PaymemoneyI 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?