Qualification > Math

How to solve these types of questions ??

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d0ckn3ss:
hi guys... i would like to know how to solve these types of equations

Lets say we have a sector of a circle OAB ( O is the origin)  


Radius is 6
Theta= Pie/3

Tangent of Point A and and tangent of point B meet at point X

1) find the length of AX
2) find the area of AXB

now i know that the length arc is r(theta) and area of sector is 1/2(r)^2(theta)
but how do i find out what AX is and the area of AXB ?

and i also attatched another question that is similar

Arthur Bon Zavi:
Solving the attachment.

(5) (i)

OA = OB

(AB)2 = (OA)2 + (OB)2
(AB)2 = (6)2 + (6)2
(AB)2 = 36 + 36
(AB)2 = 72
AB =

AB = OD

angle BAD : tan =

tan =  6/6
= tan-1 (6/6)
= 45o or =

length of arc : s = r X
                                = X
                                = 6.664324407 or 6.67 (correct to 3 significant figures)

(ii)

Area of shaded region = Area of sector ABD - Area of triangle AOB
Area of shaded region = [ X ] - [ X b X h] ]
Area of shaded region = [ X 72 X ] - [ X 6 X 6]
Area of shaded region = 9 - 18
Area of shaded region = 9 ( - 2) = 10.2743338 or 10.3 (correct to 3 significant figures)

Arthur Bon Zavi:

--- Quote from: d0ckn3ss on October 11, 2011, 03:49:38 pm ---Tangent of Point A and and tangent of point B meet at point X

--- End quote ---

This part is not clear. The tangent can be from any direction and be of any length.

d0ckn3ss:
maybee this can help you understand

attached a file

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