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Question: How do you find \(\left( h-g \right)\left( t \right)=h\left( t \right)-g\left( t \right)\) . Given \...

How do you find (hg)(t)=h(t)g(t)\left( h-g \right)\left( t \right)=h\left( t \right)-g\left( t \right) . Given h(t)=2t+1h\left( t \right)=2t+1 and g(t)=2t+2g\left( t \right)=2t+2?

Explanation

Solution

Now we are given that h(t)=2t+1h\left( t \right)=2t+1 and g(t)=2t+2g\left( t \right)=2t+2 . To find the value of (hg)(t)\left( h-g \right)\left( t \right) we will have to subtract the two functions. Hence we will consider h(t)g(t)h\left( t \right)-g\left( t \right) . Now we will simplify the obtained equation and hence find the value of (hg)(t)\left( h-g \right)\left( t \right) .

Complete step by step solution:
Now consider the given functions h(t)=2t+1h\left( t \right)=2t+1 and g(t)=2t+2g\left( t \right)=2t+2
Now we know that the given functions are linear functions in one variable where the variable is t.
Now we want to find the value of (hg)(t)\left( h-g \right)\left( t \right) . Now (hg)(t)\left( h-g \right)\left( t \right) is a nothing but the function (hg)\left( h-g \right) in t.
Now to find this function is nothing but just subtraction of two given functions.
Hence we have,
(hg)(t)=h(t)g(t)\left( h-g \right)\left( t \right)=h\left( t \right)-g\left( t \right)
Now substituting the value of function h and function g we get,
(hg)(t)=2t+1(2t+2) (hg)(t)=2t2t1 \begin{aligned} & \Rightarrow \left( h-g \right)\left( t \right)=2t+1-\left( 2t+2 \right) \\\ & \Rightarrow \left( h-g \right)\left( t \right)=2t-2t-1 \\\ \end{aligned}
Now we know that we can add and subtract the terms with the same variables and same degree, Hence we can say 2t2t=02t-2t=0 . Using this we get,
(hg)(t)=1\Rightarrow \left( h-g \right)\left( t \right)=-1

Hence the value of the function (hg)(t)\left( h-g \right)\left( t \right) is - 1. Also we can see that the function obtained is a constant function independent from variable t.

Note: Now note that we can create a new function out of two functions by adding and subtracting the function. We also have a composite function written as f(g(x))f\left( g\left( x \right) \right) . To create a composite function we substitute the value of x as a function. For example f(x)=x2f\left( x \right)={{x}^{2}} and g(x)=2x+2g\left( x \right)=2x+2 then to write the function f(g(x))f\left( g\left( x \right) \right) we will substitute the value of x=g(x)x=g\left( x \right) in f(x)f\left( x \right) . Hence we get, f(g(x))=(2x+2)2f\left( g\left( x \right) \right)={{\left( 2x+2 \right)}^{2}} similarly g(f(x))=2x2+2g\left( f\left( x \right) \right)=2{{x}^{2}}+2 .