Question

a line goes trough the points:
T(0.0) = top
P(1,2)
how do I find the function of this line( its a quadratic function)?

Answer 1

It is a parabola with the vertex at (0,0) and passes through P(1,2).
The standard form of the parabola is
y=a(x-h)^2+k
where (h,k) is the vertex, and a is a constant to be determined (by the point P).

Answer 2

i'll try to solve it now

Answer 3

@mathmate approach is correct

Answer 4

im stuck, idon't know where to start

Answer 5

ok, i get it now, is the answer 2x^2?

Answer 6

u asked for line equation pasiing thru 2 points?

Answer 7

yes. \[y = 2x^2\], is the anxwer right? a quadratic equation

Answer 8

well done

Answer 9

alternative solution

let the quadratc be y = ax^2 + bx + c --------- (1)

since its going thru T(0,0) :
0 = a(0)^2 + b(0) + c
=> c = 0 ------------(2)

since it has top at T(0, 0) :
dy/dx at x=0 is 0
=> 2ax + b = 0
=> 2a(0) + b = 0
=> b = 0 --------------------(3)

combining (1), (2) & (3)
y = ax^2 ----------------(4)

since its also going thru P(1, 2)
2 = a(1)^2
=> 2 = a ----------------(5)

plugin a=2 in (4)

y = 2x^2

Answer 10

thank you, i had to give the function in the form
y= ax^2+bx+c, so this just what i needed

Answer 11

np..