4) The area of a piece of pie in the shape of a sector is 7.1 in. The angle of the sector is 40°. Find the diameter of
the circle.

Step-by-step explanation:

Area of sector = angle/360 * pi * r^2

7.1 = 40/360 * 22/7 * r^2

7.1 = 1/9 * 22/7 * r^2

63.9 = 22r^2/7

r^2 = (7 * 63.9)/22

r^2 = 20.331818181818

r = square root of 20.331818181818

r = 4.51

d = r * 2 = 4.51 * 2 = 9.02

1.3 million hoops i believe

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places