Question 35189
find the zeros (i.e. x-intercepts) of the following functions:
1) f(x)=-48x^2+3x^4
3X^2(X^2-16)=0
X^2=0...THAT IS X=0...OR
X^2-16=0...THAT IS X^2=16...THAT IS X=4 OR -4

2) f(x)=-4x^3-15x^2+18x
X(-4X^2-15X+18)=0

X=0...OR
4X^2+15X-18=0....USE QUADRATIC FORMULA`TO GET THE ROOTS

{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{x = (-15+- sqrt( (-15)^2-4*4*(-18) ))/(2*4) }}} 
{{{x = (-15 +- sqrt( 225+288 ))/8 }}} 
{{{x = (-15 +- sqrt( 513 ))/8 }}}