Question:

Express x^2 + 4x in the form (x + a)^2 + b , stating the numerical values of a and b.

The functions f and g are defined as follows:

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(i) Show that the equation has no real roots.

(ii) State the domain of , and find an expression in terms of for .

(iii) Sketch, in a single diagram, the graph of and , making clear the relationship between these graphs.

Attempt:

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I can't complete because I get a negative value in the square root. Where did I go wrong?