7. Let g(x)=k2x2−10kx+6k+1, where k is a positive constant. The graph of y=g(x) passes fhrough (2,9).(a) Find k.(b) How many x-intercept(s) does the graph of y=−g(x)+5 have?
Q. 7. Let g(x)=k2x2−10kx+6k+1, where k is a positive constant. The graph of y=g(x) passes fhrough (2,9).(a) Find k.(b) How many x-intercept(s) does the graph of y=−g(x)+5 have?
Use Quadratic Formula: Use the quadratic formula to solve for k.k=2(4)−(−14)±(−14)2−4(4)(−8)k=814±196+128k=814±324k=814±18
Calculate Possible Values: Calculate the two possible values for k.k=814+18 or k=814−18k=832 or k=8−4k=4 or k=−0.5Since k is a positive constant, k=4.
Substitute k=4: Substitute k=4 into g(x) to find the x-intercepts of y=−g(x)+5. g(x)=42x2−10(4)x+6(4)+1 g(x)=16x2−40x+24+1 g(x)=16x2−40x+25 y=−g(x)+5=−16x2+40x−25+5 y=−16x2+40x−20
Determine X-Intercepts: Determine the number of x-intercepts by finding the discriminant of y=−16x2+40x−20.Discriminant, D=b2−4acD=(40)2−4(−16)(−20)D=1600−1280D=320
Discriminant Analysis: Since the discriminant D>0, there are two distinct real x-intercepts.