What are the domain and range of f(x) = 4* – 8? domain: {x  x is a real number}; range: {yl y> 8} domain: {x  x is a real number}; range: {yl y> 8} domain: {
Question
domain: {x  x is a real number}; range: {yl y> 8}
domain: {x  x is a real number}; range: {yl y> 8}
domain: {x  x > 4}; range: {yly>8}
domain: {x  x>4}; range: {y  y>8}
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1 Answer

1. User Answers joy123333
Answer:
domain: {x  x is a real number}
range: {y l y> 8}
Stepbystep explanation:
f(x) = 4x² – 8 is a parabola, a U shape.
Since the stretch factor, 4, is positive, it opens up, there it will have a minimum value, the lowest point in the parabola.
y > 8 because the minimum is 8.
Parabolas do not have restricted "x" values. "4" does not restrict x because it is the stretch factor, which determines how wide the parabola is.
Quadratic standard form:
f(x) = ax² + bx + c
"a" represents how wide the graph is. If it's negative it opens down, if it's positive it opens up.
"b", if written, tells you it is not centred on the yaxis. It is not written, so the vertex is on the yaxis.
"c" is the yintercept. In this case, since b = 0, it is also the minimum value.