If the relationship between two quantities is a proportional relationship, this relationship can be represented by the graph of a straight line through the origin with a slope equal to the unit rate.
Answer:
cos60° = 
Step-by-step explanation:
Using the cofunction identity
• cos(90 - x)° = sinx°, hence
sin30° = cos(90 - 30)° = cos60° = 
Since the given line

has slope

The equation of the line perpendicular to it must have a slope which is the negative reciprocal of ,

The slope of the perpendicular line

Using the slope intercept form,

We substitute

This implies that,

Since

lies on this line , it must satisfy its equation.
That is

This implies that



The line therefore has equation,