Is there’s more to this question?
Answer:
D
Step-by-step explanation:
It's a line with many solutions like
When x=1 y=1
X=2 y=-2
And so on all the pts on the line
Answer:
Solutions are 2, -1 + 0.5 sqrt10 i and -1 - 0.5 sqrt10 i
or 2, -1 + 1.58 i and -1 - 1.58i
(where the last 2 are equal to nearest hundredth).
Step-by-step explanation:
The real solution is x = 2:-
x^3 - 8 = 0
x^3 = 8
x = cube root of 8 = 2
Note that a cubic equation must have a total of 3 roots ( real and complex in this case). We can find the 2 complex roots by using the following identity:-
a^3 - b^3 = (a - b)(a^2 + ab + b^2).
Here a = x and b = 2 so we have
(x - 2)(x^2 + 2x + 4) = 0
To find the complex roots we solve x^2 + 2x + 4 = 0:-
Using the quadratic formula x = [-2 +/- sqrt(2^2 - 4*1*4)] / 2
= -1 +/- (sqrt( -10)) / 2
= -1 + 0.5 sqrt10 i and -1 - 0.5 sqrt10 i
It looks like it goes through (0,-3) and (1,2), so the gradient is (change in y)/(change in x) ->
(-3-2)/(0-1) = 5
So y=5x+b
Then as we know it passes the y axis at (0,-3) so b= -3
So we have y=5x-3