Question

set C = {x:sec^2(3x) = 1, 0<= x <= 180} (degrees)

find n(C)

Answer 1

plot the graph for sec^2(3x) and draw the line y=2 in the same graph, the no. of points of intersection give you n(C)

Answer 2

no, we're supposed to do it algaebricly.

Answer 3

*non-graphically.

Answer 4

sec^2(3x)=1+tan^2(3x)=1, so, all you have to do now is find x, for which tan^2(3x) is zero when 0<=x<=180, which comes down to tan(3x)=0

Answer 5

So, x = 0˚ or x = 180˚, hence n(C) = 2

Answer 6

no, its tan(3x)=0 not tan(x)=0

Answer 7

so, its actually 4

Answer 8

http://openstudy.com/#/updates/4ef19383e4b0dc507db6998c