The functions f(x)=8(52)x and g(x)=8(b)x are graphed in the xy-plane. For what value of b would the graphs of functions f and g be symmetric with respect to the y-axis?
Q. The functions f(x)=8(52)x and g(x)=8(b)x are graphed in the xy-plane. For what value of b would the graphs of functions f and g be symmetric with respect to the y-axis?
Find b for symmetry: To find the value of b for which the graphs of functions g(x) are symmetric with respect to the y-axis, we need to ensure that f(x)=g(−x).
Express g(−x): Let's first express g(−x) using the function g(x)=8bx.g(−x)=8b−x=bx8
Set the equation: Now we have, f(x)=8(52)x and g(−x)=8b−xWe can set them equal to each other.8(52)x=8b−xLet's simplify this equation, by multiplying by 8 on both sides of the equation.(52)x=b−x
Eliminate the exponents: To eliminate the exponents, take logarithm on both sides.log((52)x)=log(b−x)Using the properties of logarithms, Power rule: log(ab)=blog(a)xlog(52)=−xlog(b)
Solve for b: Now, we divide both sides by −x and log(52) to isolate b term.−xx=log(52)log(b)Let's start simplifying the equation:−1=log(52)log(b)Eliminate the fraction using cross-multiplication.−log(52)=log(b)Using the properties of logarithms, Negative rule: −log(ba)=log(ab)log(25)=log(b)Which implies, b=25.
More problems from Domain and range of quadratic functions: equations