Zeroes:
We must solve
To do so, we define the auxiliary variable 
. The equation becomes
The quadratic formula yields the solutions
Substituting back gives
So, the zeroes are -6, -3, 3, 6.
Turning points:
Turning points are points where a function stops being increasing to become decreasing, or vice versa. Since functions are increasing when their first derivative is positive and decreasing when it's negative, turning points are points where the first derivative is zero.
We have
If we set the derivative to be zero, we have
So, the derivative is zero if x=0 or
To prove a similarity of a triangle, we use angles or sides.
In this case we use angles to prove
∠ACB = ∠AED (Corresponding ∠s)
∠AED = ∠FDE (Alternate ∠s)
∠ABC = ∠ADE (Corresponding ∠s)
∠ADE = ∠FED (Alternate ∠s)
∠BAC = ∠EFD (sum of ∠s in a triangle)
Now we know the similarity in the triangles.
But it is necessary to write the similar triangle according to how the question ask.
The question asks " ∆ABC is similar to ∆____. " So we find ∠ABC in the prove.
∠ABC corressponds to ∠FED as stated above.
∴ ∆ABC is similar to ∆FED
Similarly, if the question asks " ∆ACB is similar to ∆____. "
We answer as ∆ACB is similar to ∆FDE.
Answer is ∆ABC is similar to ∆FED.
Firstly figure out how much money you earn per one hour. This is 312$ divided by 20 is 16$/hour. Then write an equation which represents only hourly earnings: y = 16x. To answer the last question just enter the value for variable x = 15, and you will get money earned per one week.
Answer:
3/100 times 3 is 0.09 or 9/100
