Given the function ax2+bx+c, and a is negative, how would you find b?

the y-intercept is also negative





FYI the 2 means squared.

Given the function ax2+bx+c, and a is negative, how would you find b?
Solve the formula for b





ax2+bx+c=0





ax2+c=-bx





ax2+c


--------=-b


x





-(ax2+c)


------------=b


x
Reply:given the function ax2+bx+c, and a is negative, how would you find b?





the y-intercept is also negative


Assume x is a real number





f(x) = ax^2+bx+c


f(0) = c %26lt; 0 , y intercept





from the quadratic equation





x = -b +/-sqrt(b^2 - 4ac)] / 2a


Since a is negative and c is negative, 4ac is positive.


For the radical to be a real number:





b^2 %26gt;= 4ac


b %26gt;= 2sqrt(ac) or b %26lt;= -2sqrt(ac)





That is the best I can do.
Reply:ax²+bx+c


y intercept is negative


a%26lt;0


c%26lt;0