Find the x- and y-intercepts of the graph of (x + 2y)(x - 2y) = 1?

Question

Find the x- and y-intercepts of the graph of (x + 2y)(x - 2y) = 1 .

a. x-intercept 1, y-intercept 1/ 2 (2 is a squareroot)
b. x-intercepts ±1, y-intercepts ±1/ 2 (2 is a squareroot)
c. x-intercept -1 , no y-intercept
d. x-intercepts 1, no y-intercept
e. x-intercepts ±1, no y-intercept

Answer 1

Put y = 0 => x squared = 1, x = ±1
Put x = 0 => -4y squared = 1, y = ±1/ sqrt -4 which is imaginary

so E is the answer

PS Bananaman - what happened to the 1 when you were rearranging ?

Answer 2

I am not sure what you mean by 1/5 when you mean half, but oh well -.- I have time... If you substitute the numbers in, we'll start with x, 4X = 4*5 = 20, which I know you know, but with 2y, I am not sure how you got 3, but if you do 1/2 * 2, you get 1, cancelling out the twos, So now that means that 4x + 2y = 20 + 1 = 21 Also, not sure what you mean when you say EXPLAIN 10-x squared, but ok :) Substitute again: If you mean: (10-x)^2 = (10 - 5)^2, which, with simple arithmetic, = 5^2 =25, Otherwise if you mean: 10-x^2, then substitute: 10 - 5^2 =10-25 =-15, that's all I can tell you as that part isn't explained much

Answer 3

i could never understand x-intercepts and y-intercepts... the easy way (but long way) is to graph it and find it out manually. im sorry i couldnt help more...

Answer 4

(x + 2y)(x - 2y) = 1
x + 2y = x - 2y
4y = 0
y = 0

The best answer from the choices above is e.

Answer 5

hmm... this is a tough one, i wud say e