Explain why c and d are the x-intercept and y- intercept of...?

Question

Explain why c and d are the x-intercept and y- intercept of

a) x/c + y/d = 1

How are the x- intercept and y-intercept related to c and d in:

b) x/c + y/d = 2

thanksss!!1

Answer 1

Well, in the first equation you find the x and y intercept by setting x and y to zero. If you think about it on a graph, the y intercept is when x=0 and x intercept when y=0.

So the x intercept is found from:

x/c + y/d = 1

x/c + 0/d = 1

x/c = 1

(x/c)*c = 1*c

x=c

and simlarly for the y intercept.

For your second equation you do the same substitution, with one extra step. Again to find the x intercept:

x/c + y/d = 2

x/c + 0/d = 2

x/c = 2

(x/c)*c = 2*c

x=2c

x/2=2c/2

x/2=c

(so basically it's just x over the right hand side)

I hope I helped. Good luck with the maths :)

Answer 2

The x-intercept is the x-value at the point where y = 0, and similarly for the y-intercept.  

To solve these problems, substitute 0 for x and solve for y.  Then substitute 0 for y and solve for x.