Q. write an equation of an exponential function that passes through the points (2,200) and (−1,102.4)
Understand Exponential Function: Understand the general form of an exponential function. An exponential function can be written in the form y=abx, where a is the initial value, b is the base of the exponential function, and x is the variable.
Create Equation with First Point: Use the first point (2,200) to create an equation.Substitute x=2 and y=200 into the general form y=abx to get 200=ab2.
Create Equation with Second Point: Use the second point (−1,102.4) to create another equation.Substitute x=−1 and y=102.4 into the general form y=abx to get 102.4=ab−1.
Solve System of Equations: Solve the system of equations to find the values of a and b. We have two equations: 1) 200=ab22) 102.4=ab−1 We can solve for a and b using these two equations.
Solve for a: Solve for a from the second equation.From the second equation, we can isolate a by multiplying both sides by b to get 102.4b=a.
Substitute for a in First Equation: Substitute the expression for a into the first equation.Substitute 102.4b for a in the first equation to get 200=102.4b×b2.
Simplify Equation for b: Simplify the equation to solve for b. Simplify the equation to get 200=102.4b3. Now, divide both sides by 102.4 to solve for b3. b3=102.4200b3=1.953125
Find Value of b: Find the value of b by taking the cube root of both sides.b=(1.953125)31b≈1.25
Substitute for a: Substitute the value of b back into the equation for a.Now that we have b, we can find a using the equation 102.4b=a.a=102.4×1.25a=128
Write Final Exponential Function: Write the final equation of the exponential function.Now that we have both a and b, we can write the equation of the exponential function as y=abx.y=128×1.25x
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