Q. Write an exponential function in the form y=abx that goes through the points (0,9) and (4,144).Answer:
Find 'a' value: Use the first point (0,9) to find the value of 'a'.Since the point (0,9) is on the graph of the function, when we substitute x=0, we should get y=9.So, y=ab0=a×1=a.Therefore, a=9.
Find 'b' value: Use the second point (4,144) to find the value of 'b'.We know that a=9 from Step 1, so we can substitute a and the coordinates of the second point into the equation y=abx to find 'b'.Substituting x=4 and y=144, we get 144=9b4.To solve for b, we divide both sides by 9 to isolate b4.a=90a=91To find b, we take the fourth root of both sides.a=93a=94
Write final exponential function: Write the final exponential function using the values of 'a' and 'b'.We have found that a=9 and b=2. Now we can write the exponential function as:y=ab(x)y=9×2(x)This is the exponential function that goes through the points (0,9) and (4,144).
More problems from Write a linear equation from two points