How do you do this?????
#inequality
slate cargo
late narwhal
Any tries?
clear ivy
How do you do this?????
3-x > cbrt(x)
(3-x)³ > x
27-27x+9x²-x³ > x
x³-9x²+28x-27 > 0
you can solve for x just like solving x³-9x²+28x-27 = 0, by trying each one of the factors of -27 and see which one satisfies the equation, then after that you can either use Horner's method or long polynomial division method to get the other quadratic factor, then you can find the zeroes of this quadratic factor as usual, finally from there you can find the x intervals which satisfies the original inequality
slate cargo
Hey, I go to RSM as well. What level are you?
803
slate cargo
Any tries?
A lot
slate cargo
3-x > cbrt(x)
(3-x)³ > x
27-27x+9x²-x³ > x
x³-9x²+28x-27 > 0
you can solve for x...
Why did you cube the x on the right side?
X^3
late narwhal
Cube on both sides
slate cargo
Cube on both sides
Yea but didnt they cube cbrt x two times then? Cuz cubing cbrt x should only get you x right?
The answer i got from that equation was correct but im confused on how
late narwhal
Oh yeah step 2 to 3. It's x
clear ivy
But the equation gave me the right answer help
then it's a coincident, right answer doesn't mean the process is also right