Outside temperature over the course of a day can be modeled as a sinusoidal function. suppose you know the high temperature of 109 degrees occurs at 6 pm and the average temperature for the day is 68 degrees. find the temperature, to the nearest degree, at 3 am.
it would only take three hours.
x + 6=3x
you went wrong on the 4th line while expanding the parentheses.
(x^2 + 2x)(x^2 + 2x) - 4
= x^4 + 2x^3 + 2x^3 + 4x^2 - 4
= x^4 + 4x^3 + 4x^2 - 4. (answer).