Exponential Equation In Quadratic Form

In summary, the conversation discusses solving a problem involving the equation 3^2x+3^(x+1)-4=0 by using the substitution method. One person suggests substituting u = 3^x and then solving for u using the quadratic formula. The other person advises approaching the problem step by step and substituting back in to solve for x.
  • #1
chillfactor
12
0

Homework Statement


The problem is 3^2x+3^(x+1)-4=0

I know I had to solve it by substitution


Homework Equations





The Attempt at a Solution


I had u = 3^x
I put it in:
(u )(u ), but I was not sure how to get the middle term 3^(x+1)
 
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  • #2
You could write 3^(x+1) = 3^x * 3^1
 
  • #3
chillfactor, that's a bad way to do it. Take this slowly, step by step.
First make the substitution, then once it is in the general quadratic form [tex]au^2+bu+c=0[/tex] THEN solve for u either by factorizing or using the quadratic formula. After doing that, substitute back in and solve for x.
 

1. What is an exponential equation in quadratic form?

An exponential equation in quadratic form is an equation that combines elements of both exponential and quadratic equations. It has the form of y = ax^2 + bx + c, where x represents the base of the exponential term and a, b, and c are constants.

2. What are the steps for solving an exponential equation in quadratic form?

The steps for solving an exponential equation in quadratic form are as follows:

  1. Isolate the exponential term on one side of the equation.
  2. Take the natural logarithm of both sides of the equation.
  3. Use the properties of logarithms to simplify the equation.
  4. Use the quadratic formula to solve for x.
  5. Check your solution by plugging it back into the original equation.

3. What are some real-life applications of exponential equations in quadratic form?

Exponential equations in quadratic form are commonly used in fields such as finance, physics, and biology. Some real-life applications include calculating compound interest, modeling population growth, and predicting the trajectory of a projectile.

4. How do you graph an exponential equation in quadratic form?

To graph an exponential equation in quadratic form, you can use a graphing calculator or manually plot points by substituting different values for x and solving for y. The resulting graph will be a parabola with a vertical stretching or compression depending on the value of a and a horizontal translation depending on the value of b.

5. Can an exponential equation in quadratic form have complex solutions?

Yes, an exponential equation in quadratic form can have complex solutions. This occurs when the value inside the square root in the quadratic formula is negative. Complex solutions can also arise when the base of the exponential term is a complex number.

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