# What is the right choice for question 5) ? http://postimg.org/image/y6nshwmef/

### 1 Answer | Add Yours

Given the function y=sin(2x)-1, we are asked to find the slope of the secant line between `x=30^@` and `x=60^@` .

The slope of the secant line between two points `(x_1,y_1),(x_2,y_2)` is `m=(y_2-y_1)/(x_2-x_1)`

`y_(30^@)=sin[2(30^@)]-1=sin(60^@)-1=sqrt(3)/2-1`

`y_(60^@)=sin[2(60^@)]-1=sin(120^@)-1=sqrt(3)/2-1`

`y_(60^@)-y_(30^@)=sqrt(3)/2-1-(sqrt(3)/2-1)=0` .

**Therefore the slope is zero, and the answer is (a).**