State how many imaginary and real zeros the function has. f(x) = x3 + 5x2 - 28x - 32
Solution:
It is given that,
f(x) = x3 + 5x2 - 28x - 32
Now we have to find the number of imaginary and real zeros the function has.
Since x = -1 is the zero of the given polynomial, therefore x + 1 is the factor of f(x) = x3 + 5x2 - 28x - 32.
We need to perform factorization of f(x) = x3 + 5x2 - 28x - 32
By using long division method ;
Above equation can be written as,
= (x + 1) (x2 + 4x -32),
Now we have to perform factorization of (x2 + 4x -32),
by using middle term factorisation,
= (x + 1) (x2 + 8x - 4x -32)
= (x + 1) (x(x + 8) - 4 (x + 8))
= (x + 1) (x - 4) (x + 8)
From the solution, we clearly see that there were three real zeros in the given function.
Therefore, the function has 0 imaginary and 3 real zeros.
State how many imaginary and real zeros the function has. f(x) = x3 + 5x2 - 28x – 32
Summary:
The function f(x) = x3 + 5x2 - 28x - 32 has 0 imaginary and 3 real zeros.
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