determine the trend of each linear function: 1. f(x)= 3x+5

I don't know what you call the "trend" or why you call this a trigonometry question. It is about algebra.

The value of the function increases with x at a rate of three times the change in x.

The trend of the linear function f(x) = 3x + 5 is a positive slope. This means that as x increases, the value of the function also increases. The rate of change is constant and equal to 3, which indicates that for every increase of 1 in x, the value of the function increases by 3.

To determine the trend of a linear function, you need to look at the coefficient of the x term in the function. In this case, the coefficient of x is 3.

Since the coefficient is positive, this means that the value of the function will increase as x increases. More specifically, for each unit increase in x, the value of the function will increase by 3.

Therefore, the trend of the function f(x) = 3x + 5 is an increasing trend.