Use logarithms to solve.e2x−ex−56=0Enter the exact answer (i.e. keep your answer in exponential or logarithmic form, you do not need to calculate its numeric value). Enclose arguments of functions in parentheses and include a multiplication sign between terms. For example, c∗ln(h).
Q. Use logarithms to solve.e2x−ex−56=0Enter the exact answer (i.e. keep your answer in exponential or logarithmic form, you do not need to calculate its numeric value). Enclose arguments of functions in parentheses and include a multiplication sign between terms. For example, c∗ln(h).
Substitute with new variable: Let's substitute ex with a new variable, say y. So we have y=ex. This will simplify the equation.
Quadratic equation: Now, our equation becomes y2−y−56=0, which is a quadratic equation.
Factor the equation: We can factor this quadratic equation: (y−8)(y+7)=0.
Solve for y: Setting each factor equal to zero gives us y−8=0 or y+7=0.
Consider positive value: Solving for y, we get y=8 or y=−7. But since y=ex and ex is always positive, y cannot be −7.
Substitute back: So we only consider y=8. Now we substitute back ex for y, getting ex=8.
Take natural logarithm: To solve for x, we take the natural logarithm of both sides: ln(ex)=ln(8).
Solve for x: Using the property of logarithms that ln(ex)=x, we have x=ln(8).