Q. Write an exponential function in the form y=abx that goes through the points (0,19) and (7,2432).Answer:
Find 'a' value: To find the exponential function, we need to determine the values of 'a' and 'b' in the equation y=abx. We can use the point (0,19) to find 'a' because any number raised to the power of 0 is 1. So, the equation becomes y=a⋅1, which simplifies to y=a. Since the function passes through (0,19), we can set y to 19 and solve for 'a'.Calculation: 19=a⋅1(0,19)0
Find 'b' value: Now that we have the value of 'a', we need to find 'b'. We can use the second point (7,2432) to find 'b'. We substitute 'a' with 19 in the equation y=abx and then solve for 'b'.Calculation: 2432=19⋅b7b7=192432b7=128
Calculate 'b': To find 'b', we need to take the seventh root of 128. The seventh root of a number is the same as raising that number to the power of 71.Calculation: b=(128)71b≈2
Check approximation: We need to check if b≈2 is a correct approximation. Since 27=128, we can confirm that b=2 is the exact value and not just an approximation.Calculation: 27=128
Write exponential function: Now that we have both a and b, we can write the exponential function. We have a=19 and b=2, so the function is y=19×2x.