coordinates of a point where the line x=-5 meets the parabola

[Luffy]

Hello,

I need bit of direction ref the below equation.

y = 0.2x^2+0.15^2+0.8

I must substitute x=-5 into the equation to find the coordinates of the point where x=-5 meets the parabola.

I have attempted to solve this:

y=0.2*(-5)+0.15*(-5)+0.8

gives

y=-0.95

Is there another point to this question as it mentions finding coordinates? I presume it wants me to find the x-intercept? Any advice would be much appreciated.

 

[Luffy]

Denis,

Apologies - I entered the equation incorrectly.

The equation is y = 0.2x^2 + 0.15x + 0.8

I must substitute x = -5 into the equation to find the coordinates of the point where the line x = -5 meets the parabola.

Am I right in thinking that

y = 0.2*(-5) + 0.15*(-5) +0.8

so y = -0.95

If so, is there another coordinate I need to find?

 

[Deleted member 4993]

Denis,

Apologies - I entered the equation incorrectly.

The equation is y = 0.2x^2 + 0.15x + 0.8 = 5.05

I must substitute x = -5 into the equation to find the coordinates of the point where the line x = -5 meets the parabola.

Am I right in thinking that

y = 0.2*(-5)^2 + 0.15*(-5) +0.8 .... you are missing the square

so y = -0.95

If so, is there another coordinate I need to find?

.

 

[Ishuda]

Hello,

I need bit of direction ref the below equation.

y = 0.2x^2+0.15^2+0.8

I must substitute x=-5 into the equation to find the coordinates of the point where x=-5 meets the parabola.

I have attempted to solve this:

y=0.2*(-5)+0.15*(-5)+0.8

gives

y=-0.95

Is there another point to this question as it mentions finding coordinates? I presume it wants me to find the x-intercept? Any advice would be much appreciated.

When you have a function [which this, corrected equation, gives], an input of an x value can only give one value at most. Thus your [again corrected] working
y=0.2*(-5)^2+0.15*(-5)+0.8 = 5.05
would give the coordinates of the point. In general, given a function y(x) such as given here, the coordinates is the point (x,y) where you provide the x (here x=-5) and the equation provides the y (here y=5.05). Thus, in this case, the coordinates are (-5, 5.05).