Help me to solve this question please?

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1 Answer
Oct 28, 2017

I got #a = 1# and #b = 2#.

Explanation:

First of all, I assume we are just solving for #a# and #b#, since there is no #k# in the equation for #f(x)#.

For #f(x)# to be continuous, we need #ax +b# to have the same y-coordinate at #x = -1# as would #x^2#. Because #(-1)^2 = 1#, we can set #ax + b# to #1#.

#a(-1) + b = 1#

If we repeat the same process, we get the second equation.

#a(2) + b = 4#

If we solve by substitution, we get

#2a + 1 + a = 4#

#3a = 3#

#a = 1#

It follows that #b = 2#. The answer is therefore #a#.

We confirm graphically

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As you can see, the graph is continuous on all #x#.

Hopefully this helps!