Answer:
-4/5
Step-by-step explanation:
To find the slope of the tangent to the equation at any point we must differentiate the equation.
x^3y+y^2-x^2=5
3x^2y+x^3y'+2yy'-2x=0
Gather terms with y' on one side and terms without on opposing side.
x^3y'+2yy'=2x-3x^2y
Factor left side
y'(x^3+2y)=2x-3x^2y
Divide both sides by (x^3+2y)
y'=(2x-3x^2y)/(x^3+2y)
y' is the slope any tangent to the given equation at point (x,y).
Plug in (2,1):
y'=(2(2)-3(2)^2(1))/((2)^3+2(1))
Simplify:
y'=(4-12)/(8+2)
y'=-8/10
y'=-4/5
Set y equal to 25 because this is the amount of money Aisha wants to save. This gives you 25 = 50-1.99x. Now we can solve for x, which is the variable. First, subtract 50 from both sides so that you can get the variable, x, by itself. After subtracting 50 from both sides, you are left with -25 = -1.99x . If it is easier for you, you can put the numbers on opposite sides so it reads -1.99x = -25 . Now divide both sides by -1.99 so that x is by itself. So -1.99x ÷-1.99 = 1x which is equal to just x and -25÷-1.99 = about 12.56, which is a decimal. (Remember that when you divide a negative number by a negative number, it becomes a positive number) Finally we have x = 12.56 (or 1x = 12.56) with 12.56 being equal to the number of songs Aisha can buy if she also wants to save money in her bank account. However, nobody can buy only .56 or part of a song. Round down to the nearest whole number, which is 12. This is how many songs she can buy and it makes sense because it is 12 entire songs, not 12 and just the chorus of a song. If you want to check, you can plug in 12 for x and she shouod have a little more than $25 in her bank account. So Aisha can buy 12 songs is she wants to save $25. I hope this helped :)
Answer:
0, 5, 8, 9, 8, 5, 0
Step-by-step explanation:
Using the cosine double angle formula,
(Note I took the positive case since 
terminates in the first quadrant)
Using the Pythagorean identity,
(Note I took the positive case since terminates in the first quadrant)
She has $9.90 saved, she needs $35.10 more to buy the gift
