Q. A polynomial function M is defined asM(x)=(2x−3)(x2+3x+10)If M(a)=0 for some real number a, then what is the value of a ?
Given Polynomial Function: We are given the polynomial function M(x)=(2x−3)(x2+3x+10). To find the value of a such that M(a)=0, we need to set the function equal to zero and solve for x.
Factors of M(x): The function M(x) is the product of two factors: (2x−3) and (x2+3x+10). For the product to be zero, at least one of the factors must be zero.
Setting Linear Factor to Zero: First, let's set the linear factor equal to zero and solve for x: 2x−3=0.Adding 3 to both sides gives us 2x=3.Dividing both sides by 2 gives us x=23.
Solving the Quadratic Factor: Now, let's consider the quadratic factor: x2+3x+10=0.This is a quadratic equation, and we can attempt to solve it using the quadratic formula, factoring, or completing the square. However, we can also check the discriminant (b2−4ac) to see if there are real solutions. For this quadratic, a=1, b=3, and c=10.
Checking the Discriminant: The discriminant is b2−4ac=(3)2−4(1)(10)=9−40=−31.Since the discriminant is negative, there are no real solutions to the quadratic equation x2+3x+10=0.
Real Solutions for M(x): Since the quadratic factor does not have real solutions, the only real solution for M(x) = 0 comes from the linear factor 2x−3=0, which we solved as x=23.Therefore, the value of a for which M(a)=0 is a=23.
More problems from Domain and range of quadratic functions: equations