Q. If the factors of the quadratic function (g) are (x – 7) and (x + 3), what are the zeros of function (g)?
Answer
Given \( (x-7)(x+3)=0 \).
Solve \(x-7=0\Rightarrow x=7\) and \(x+3=0\Rightarrow x=-3\).
Zeros: \(7,\ -3\).
Detailed Explanation
Step 1 — Definition of a zero. A zero of the function g is any real number x for which g(x) = 0.
Step 2 — Express g(x) using its factors. If the given factors of g are (x − 7) and (x + 3), then g(x) has the form \(g(x)=k(x-7)(x+3)\) for some constant \(k\neq 0\). The constant factor \(k\) does not affect the zeros.
Step 3 — Set the function equal to zero and apply the zero-product property. To find zeros we solve \(g(x)=0\), which gives
\((x-7)(x+3)=0\)
The zero-product property states that if a product of two factors equals zero, then at least one of the factors must be zero. Thus we solve the two simple equations separately:
- Solve \(x-7=0\), which yields \(x=7\).
- Solve \(x+3=0\), which yields \(x=-3\).
Step 4 — Verify by substitution (optional check).
- For \(x=7\): \((7-7)(7+3)=0\cdot 10=0\).
- For \(x=-3\): \((-3-7)(-3+3)=(-10)\cdot 0=0\).
Conclusion. The zeros of g are \(x=7\) and \(x=-3\).
Algebra FAQs
What are the zeros of \(g\) if the factors are \(x-7\) and \(x+3\)?
How do you write \(g(x)\) from the factors?
What is the axis of symmetry and the vertex of this quadratic?
What is the y-intercept of \(g(x)\)?.
What are the sum and product of the zeros, and how do they relate to coefficients?
What happens if a factor is repeated (multiplicity)?
How can you check the zeros by expanding and solving?
What is the end behavior of this quadratic function?
Try our economics and finance help
Analytical, General, Biochemistry, etc.