Finding x when y = 0 for y = 3x - x³/2

[jinx007]

A curve equation is y = 3x - x^3/2

find the value of X when y=0

please help me i don't know how to proceed..!

 

[thrill3rnit3]

0 = 3x - x³/2
x³/2 = 3x

tell me if you still need help after that

 

[jinx007]

0 = 3x - x³/2
x³/2 = 3x

tell me if you still need help after that

Yes infact its there that i am stuck..!

 

[jinx007]

0 = 3x - x³/2
x³/2 = 3x

tell me if you still need help after that

i want to know how to find the value of x

 

[berkeman]

i want to know how to find the value of x

x³/2 = 3x

[STRIKE]Hint -- remember that in working with equations, you want to do the SAME thing to both sides of the equation, while working to simplify everything. What operation can you do to both sides of this equation to get rid of an x on both sides...?[/STRIKE]

EDIT -- oops, see better hint later by Mark44

 

[thrill3rnit3]

Don't forget the case x=0 though.

 

[Mark44]

0 = 3x - x³/2
x³/2 = 3x

tell me if you still need help after that

Writing the equation as x³/2 = 3x is NOT a good strategy. Instead, work with x³ - 6x = 0 (equivalent to the one you started with) and factor the cubic expression.

 

[thrill3rnit3]

They both yield the same answers, except that you lose the solution x=0 if you do the first method. I'm sorry if I forgot to make that clear.

 

[Mark44]

They both yield the same answers, except that you lose the solution x=0 if you do the first method. I'm sorry if I forgot to make that clear.

That's why factoring is a better strategy - you don't lose solutions.