The graph represents the relation y = xo2 - 3x - 3. Find the value of x for which x2 - 3x = 7
A. -1.55, 4.44 B. 1.55, -4.55 C. -1.55, -4.55 D. 1.55, 4.55
Correct Answer: A
Explanation
x2 - 3x = 7 x2 - 3x - 7 = 0 What can you add to both sides of the equation to give the same value of y = x2 - 3x - 3 The number is 4 x2 - 3x - 7 + 4 = 4 x2 - 3x - 3 = 4 but y = x2 - 3x - 3 y = 4; So are y = 4 draw a line parallel to x axis, to cut or intersect the graph. At these points look down to see the corresponding values on x axis This give -1.55 and 4.55
