Q. The function k is given by k(x)=3x2−19x−14. Find all values of x for which k(x)>0.
Factor quadratic equation: Find the roots of the quadratic equation by factoring k(x)=3x2−19x−14.k(x)=(3x+1)(x−14)Set each factor equal to zero to find the roots.3x+1=0 and x−14=0
Solve for roots: Solve for x in each equation.For 3x+1=0, x=−31For x−14=0, x=14
Determine intervals to test: Determine the intervals to test around the roots.We have two intervals: x<−31, −31<x<14, and x>14.
Choose test points: Choose test points from each interval and plug them into k(x). For x<−31, use x=−1. For −31<x<14, use x=0. For x>14, use x=15.
Evaluate k(x): Evaluate k(x) at each test point.k(−1)=3(−1)2−19(−1)−14=3+19−14=8k(0)=3(0)2−19(0)−14=−14k(15)=3(15)2−19(15)−14=675−285−14=376
Determine where k(x)>0: Determine where k(x) is greater than 0 based on the test points.k(x)>0 when x<−31 and when x>14.
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