Algebra
posted by Aria on .
Could someone verify if I got two answers to two problems right?
f(x)=x^29x+15 find x and y intercepts
9+square root of 21/2,0
9square root of 21/2,0
x^2x+3=0 solve and find xintercepts
(1+square root of 11/2,0)
(1square root of 11/2,0)

for ax^2 + bx + c = 0,
x = (b ± √(b^2  4ac) )/(2a)
so for yours, for the xintercepts
x = (+9 ± √(814(1)(15))/2
= (9 ± √21)/2
for the yintercept, let x=0
f(0) = 09+15 = 15
for the second:
xintercept: (1 + √11)/2 , (you had 1 + √11/2 > only the last term was divided by 2 )
yintercept : 3 
Hi
I don't understand how you are getting the y intercept. I am so confused about which numbers are solutions, vertex, xintercepts, yintercepts etc.
Can you write out an example of an equation and how you get each number from a formula. I have been in this class for nine weeks and with all the information I have at my disposal I still am confused.