## Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.

## Question

secondary 4 | A Maths

Help Athl3! Anyone can contribute an answer, even non-tutors.

##### Athl3

chevron_right

A math

Date Posted: 5 years ago
Views: 286
Muhd Ilman Fahmi
5 years ago
i) Draw a perpendicular drop from B to AO (call the line on AO 'x'), and draw a horizontal on C to that vertical line. You now have 2 right angle triangles.

You can see that in the small triangle, the angle CBX is theta degrees. The length of AX is 12*cos(theta), and the length OX is the same as 5sin(theta)

ii) You can just simply use the R formula to get that expression in those terms.

iii) You can see that at maximum OA, R must be multiplied by 1 (largest value of sine is 1). Therefore sin(theta + alpha) has to be 1. You can work backwards to find the value of theta.

iv) Just substitute OA to be 8 = Rsin(theta+alpha). Simple trigonometry will get you theta at 8cm.

Go try it out! Hope it helps