Triangle ABC is equilateral, because AB=BC=AC=a. Then
m∠A=m∠B=m∠C=60°.
Let point D lie on the ray BC to the right from points B and C and let CD=x. Then BD=a+x, AB=a.
Consider triangle ACD. In this triangle, m∠ACD=180°-m∠ACB=180°-60°=120°.
By the cosine theorem,
Since then
and
Therefore, you get double inequality
or
Answer:
<em>y = 8.25x</em>
Step-by-step explanation:
<u>Linear Modeling</u>
Some events can be modeled as linear functions. If a situation comes where a linear model is suitable, then we need two sample points to make the model and predict unknown behaviors.
The linear function can be expressed in the slope-intercept format:
The equation of a line passing through points (x1,y1) and (x2,y2) can be found as follows:
Let's use linear modeling to represent Steven's earnings he makes babysitting. Call y the money he charges by x hours of work.
We know he charges y1=$33 for x1=4 hours, and y2=$57.75 for x2=7 hours. The ordered pairs are (4,33) and ( 7, 57.75)
Computing the equation of the line we have:
Operating:
y = 8.25x
There is a proportional relationship.