Which expression is equivalent to (4 + 6i)2?

2 answers:

8 0

$\bf \textit{recall that }i^2=-1\\\\
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(4+6i)^2\implies (4+6i)(4+6i)\implies 16+24i+24i+36i^2
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16+48i+36(-1)\implies 16+48i-36\implies -20+48i$

Allisa [31]3 years ago

7 0

If you mean $(4+6i)^2$ then
remember that $i=\sqrt{-1}$ and that $i^2=-1$
just treat 'i' as a variable for the expansion part
$(4+6i)^2=$ $(4+6i)(4+6i)=$ $(4*4)+(6i*4)+(4*6i)+(6i*6i)=$ $16+24i+24i+36i^2=$ $16+48i+36(-1)=$ $16+48i-36=$ $-20+48i$
you didn't give us the expressions so you will have to see which one of them is equivilent ot -20+48i

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Graph the function by making a table of values which table is correct

Talja [164]

It is often more convenient to evaluate a polynomial when it is written is "Horner form."

... f(x) = (((10x -4)x -8)x +3)x -6

The graphs offered can be distinguished by their values of f(1) and f(2), so our table can be a short one.

... f(1) = (((10·1 -4)1 -8)1 +3)1 -6 = -5 . . . . . . . eliminates graph d

... f(2) = (((10·2 -4)2 -8)2 +3)2 -6 = 96 . . . . eliminates graphs a and c

The appropriate choice is b.