This is question 20, Exercise 6C.
"Find the equations of the four tangents common to the hyperbola x^2 - 2y^2 = 4 and the circle x^2 + y^2 = 1. Find the points of contact of these tangents with the circle." [Hint: Let xx1 + yy1 = 1 be tangent to x^2 + y^2 = 1 at P(x1, y1)]
Here's what I tried...
Hey, I just can't seem to prove this identity:
[1 + cosec^2 (A) tan^2 (C)] [1 + cot^2 (A) sin^2 (C)]
______________________ = ___________________
[1 + cosec^2 (B) tan^2 (C)] [1 + cot^2 (B) sin^2 (C)]
It'll be of great help if someone could solve this. Thanks.
I'm stuck on question 28 Exercise 5E on the Patel 4 Unit book.
"Show that the polynomial x^n +mx - b = 0 has a multiple root provided (m/n)^n + (b/(n-1))^(n-1) = 0. Find this root."
I've tried solving it simultaneously but didn't arrive at the relation stated by the book.
Any help...
Suppose that z^7 = 1 where z=/=1
(i) Deduce that z^3 + z^2 + z + 1 + 1/z + 1/z^2 + 1/z^3 = 0
(ii) By letting x = z + 1/z reduce the equation in (i) to a cubic equation in x.
(iii) Hence deduce that
(cos pi/7)(cos 2pi/7)(cos 3pi/7) = 1/8
I got (i) and (ii) but have no idea on how to...