Two quadratic problems...

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June 24th 2009, 05:36 AM
M23

Two quadratic problems...

The x-intercepts of the graph of a quadratic function are -2 and 3. What is the equation of the axis of symmetry? A. x = 0.5 B. x = 1.0 C. x = -0.5 D. x = -1.0 .................................................. .................................................. .................................................. ...................2. The hypotenuse of a right triangle is 34 cm in length. One leg of the triangle is 14 cm longer than the other leg. If the length of the shorter leg is represented by x, a quadratic equation that can be used to determine the lengths of the legs is A. x2 + 14x - 480 = 0 B. x2 + 14x - 676 = 0 C. x2 - 14x - 480 = 0 D. x2 - 14x - 676 = 0 I've tried getting the answer, but it does not seem to match up with the choices. Thanks for the help!
June 24th 2009, 05:44 AM
SENTINEL4

Quote:

Originally Posted by M23

The hypotenuse of a right triangle is 34 cm in length. One leg of the triangle is 14 cm longer than the other leg. If the length of the shorter leg is represented by x, a quadratic equation that can be used to determine the lengths of the legs is A. x2 + 14x - 480 = 0 B. x2 + 14x - 676 = 0 C. x2 - 14x - 480 = 0 D. x2 - 14x - 676 = 0

If one side is 14 cm longer than the shorter then you have :
shorter = x so the other x+14

Use Pythagoras Theorem and you have

$x^2 + (x+14)^2 = 34^2 \Rightarrow ... \Rightarrow x^2+14x-480=0$
June 24th 2009, 05:52 AM
masters

Quote:

Originally Posted by M23

The x-intercepts of the graph of a quadratic function are -2 and 3. What is the equation of the axis of symmetry?
A. x = 0.5
B. x = 1.0
C. x = -0.5
D. x = -1.0

The axis of symmetry will pass through the midpoint of the x-intercepts. What is halfway between -2 and 3?