The one you've chosen certainly shows positive function values, but there is another region also. Note that positive function values occur where the y-values are positive.
Remembering that even means f(-x) = f(x) and that odd means f(-x) = -f(x), you should find the following graph helps:
(Hint: does f(-1) = f(1), -f(1), or neither of these?)
The number you add is the complex number a + bi, which here is -1 + 12i.
Force required = µs*weight = 0125*0.382*9.8 N
Let the unknown (complex) number be a + bi
Then 3 - 5i + a + bi = 2 + 7i
Subtract 3 - 5i from both sides: a + bi = 2 + 7i - 3 + 5i or a + bi = -1 + 12i
Equating real and imaginery parts we have: a = -1, b = 12.
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As below:
Like so:
As follows:
As Guest notes, the denominator should be Σf, so:
Σ(fx)/Σf = 3.667, or mean number of pets per person ≈ 3.7
Let y = x2. Then y2 - 2y - 7 = 0.
Use the standard quadratic formula to find that y = 2√2 + 1 and y = 1 - 2√2
Since x = ±√y we must have positive y for real roots. Only 2√2 + 1 is positive, hence there are just two real roots of the original equation.
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