What is the missing statement for step 6?

To find the inverse of a number a, one can use the equation f(c) = a-1/c=0 where c is the inverse of a use the secant method of finding roots of equations to find the inverse of a = 2.5 ,er = 0.001%

6. sarah saved $12.75 every week for a number of weeks, w. she received an additional $25 during the last week in which she saved money. write and solve an equation to find the number of weeks, w, for which sarah had saved money if she has $114.25 now.

If 0° ≤ θ ≤ 90° and cosθ = 11 15 , what is the value of sin (90° - θ)? a) 11 /15 b) 15/ 11 c) 15 /4 d) 4/15