Queries with Functions (1 Viewer)

[Lukybear]

If f(x) = ax^2 + bx + c , find a,b,c so that f(1)=0, f(-1) = 0, f(-2) = 15



Ive got a=5, b=0, and c=-5. The answers were different tho, yet still right.
a=2, b=-3 and c=1. Im interested in why thats the case, and would HSC present such a question?

 

[omniscience]

If f(x) = ax^2 + bx + c , find a,b,c so that f(1)=0, f(-1) = 0, f(-2) = 15



Ive got a=5, b=0, and c=-5. The answers were different tho, yet still right.
a=2, b=-3 and c=1. Im interested in why thats the case, and would HSC present such a question?

i dun no how to do it

but 1 + 1 =2, keep that in mind. make sure ur basics are tight

 

[kurt.physics]

If f(x) = ax^2 + bx + c , find a,b,c so that f(1)=0, f(-1) = 0, f(-2) = 15



Ive got a=5, b=0, and c=-5. The answers were different tho, yet still right.
a=2, b=-3 and c=1. Im interested in why thats the case, and would HSC present such a question?

I also got the same answer as you, the textbook must be wrong. The answer they gave is wrong as it doesnt satisfy f(-1) = 0

 

[Lukybear]

omg... im such a idiot. I check the answers against the equation and i thought it was right as well... Such silly mistakes...

 

[Drongoski]

omg... im such a idiot. I check the answers against the equation and i thought it was right as well... Such silly mistakes...

If 2 quadratics have >= 3 points in common then they are the same quadratic; can't be 2 distinct ones. Besides f(-1) = 6 with the book's answer.