exercise:Dc76246b0e

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Let [math]f[/math] and [math]g[/math] be two functions defined, respectively, by

[[math]] f(x)= x^2 + x + 1, -\infty \lt x \lt \infty , [[/math]]

[[math]] g(x)= \frac{x + 1}{x - 1}, \mbox{for every real number $x$ except $x=1$}. [[/math]]

Find:

• [math]f(2)[/math], [math]f(0)[/math], [math]f(a)[/math], [math]f(a + b)[/math], [math]f(a - b)[/math].
• [math]g(0)[/math], [math]g(-1)[/math], [math]g(10)[/math], [math]g(5 + t)[/math], [math]g(x^3)[/math].