Mathematics Help!

[diwakarchopra]

I was going through some past papers and I got stuck in part (b) of the question. Kindly help me out.

 

[PeterG]

Hi,

OC is simply the addition of the two radius of the circles, since it is a straight path linking both of the centers of the circles.

To find PT:

For this you'll need trigonometry: Draw a straight line from C so that it reaches the OP tangent and you will have a right angled triangle! You already know OC, which is your a2 of the a2 = b2 + c2 and now, you have your b2 by doing 6 - 4.

If you didn't understand from my explanation, I can explain again

 

[UxaiR]

draw a dotted horizontal line toward the line OP, and where the line meets mark that point "X"

Now OX would be 6 - 4 = 2 cm

then you can calculate the value of XC easily

OC^2 = OX^2 + XC^2

XC = PT (as they are parrallel)


have a look at the below diagram

 

[diwakarchopra]

Thank You PeterG and UxaiR for helping me out in this question.

 

[PeterG]

Not a problem!