A circle has a sector with area 45/4 pi and central angle of 9/10 pi radians. What is the area of the circle?

the area of the circle: 25π

Step-by-step explanation:

45/4 π = 11.25π

9/10π = 0.9π

11.25π / 0.9π = x / 2π   360° = 2π

x = (11.25π x 2π) / 0.9π = 25π

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

thus, the first answer choice, y = sec x, is the correct one