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What are the excluded values for the rational expression #(5d+15)/(d^2-d-12)#?

Answer 1

Julia Adams

#d!= -3 and d!=4#

the excluded values are those which will make the denominator equal to #0#

Factorise to find the factors

#(5(d+3))/((d-4)(d+3))#

#d!= -3 and d!=4#

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Answer 2

Jameson Allen

The excluded values for the rational expression (5d+15)/(d^2-d-12) are the values of d that make the denominator equal to zero. In this case, the denominator is (d^2-d-12). To find the excluded values, we need to solve the equation d^2-d-12=0. Factoring the equation, we get (d-4)(d+3)=0. Setting each factor equal to zero, we find that the excluded values are d=4 and d=-3.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.