If c(x)=5/x-2 and d(x)=x+3 what is the domain of (cd)(x)?. . And, if f(x)=7+4x and g(x)=1/2x, what is the value of (f/g)(5)?
Answer:
Domain of (cd)(x) is all real numbers values except 2.
The value of (f/g)(5) is 270
Step-by-step explanation:
Given c(x) and d(x) we have to find the domain of (cd)(x)
\(c(x)=\frac{5}{x}-2\) and \(d(x)=x+3\)
The product of above two is
\((cd)(x)=c(x)d(x)=(\frac{5}{x-2})(x+3)\)
The above function is defined at all real numbers values except 2 because that would make the denominator 0.
Hence, domain of (cd)(x) is all real numbers except 2.
Given \(f(x)=7+4x\) and \(g(x)=\frac{1}{2x}\)
we have to find the value of (f/g)(5)
\(\text{(f/g)x=}\frac{7+4x}{\frac{1}{2x}}=2x(7+4x)\)
put x=5
\(\text{(f/g)(5)=}2x(7+4x)=2(5)(7+4(5))=10(27)=270\)