Thanks to everyone who answers
Here's the problem.
The question asks to find all the roots of the following problem:
y= x cubed minus 18x
my teacher used the difference of squares to find the roots but it was to the 4th, so I got it, but with the cubed, I do not understand. Thank you , thank you, so much. Happy Holidays!!!!!!!!
Here's the problem.
The question asks to find all the roots of the following problem:
y= x cubed minus 18x
my teacher used the difference of squares to find the roots but it was to the 4th, so I got it, but with the cubed, I do not understand. Thank you , thank you, so much. Happy Holidays!!!!!!!!
-
y = x³ - 18x
roots are when y = 0
0 = x³ - 18x
factor out x
0 = x(x²-18)
because of the multiplicative property of 0, this gives us 2 equations: x = 0 and x²-18 = 0
x = 0 is already solved
x²- 18 = 0
add 18 to each side
x² = 18
take the root of each side and factor 9 out of the radical
x = ± 3√2
Solution: x = {3√2, -3√2, 0}
hope I helped
roots are when y = 0
0 = x³ - 18x
factor out x
0 = x(x²-18)
because of the multiplicative property of 0, this gives us 2 equations: x = 0 and x²-18 = 0
x = 0 is already solved
x²- 18 = 0
add 18 to each side
x² = 18
take the root of each side and factor 9 out of the radical
x = ± 3√2
Solution: x = {3√2, -3√2, 0}
hope I helped
-
Express as y=x(x^2 -18) and take it from there.
-
if its so easy , then why dont you just do it yourself ?