Answer: d
The two smallest sides have to add up to the largest one
I think that you are mistaking the memory tool for something else
or a math book is trying to make math cute by calling them 'socatoa joe' and 'mr. pi' and such
anyway, SOH, CAH, TOA is the way to remember
Sine=oposite/hypotonuse
Cosine=adjacent/hypotonuse
Tangent=oposite/adjacent
(oposite side=side oposite the angle
adjacent is the side touching the angle that is not they hypotonuse
and of course the hypotonuse is the longest side aka, side oposite right angle)
for a spade to be pulled from a deck of cards is 13/52 chance.
for you to pull an ace from the deck is 4/52.
Answer:
Step-by-step explanation:
Given the expression cosec (x) = 4 and tan(x)< 0
since cosec x = 1/sinx
1/sinx = 4
sinx = 1/4
From SOH, CAH TOA
sinθ = opposite/hypotenuse
from sinx = 1/4
opposite = 1 and hypotenuse = 4
to get the adjacent, we will use the Pythagoras theorem
adj² = 4²-1²
adj² = 16-1
adj ²= 15
adj = √15
cosx = adj/hyp = √15/4
tanx = opposite/adjacent = 1/√15
since tan < 0, then tanx = -1/√15
From double angle formula;
sin2x = 2sinxcosx
sin2x = 2(1/4)(√15/4)
sin2x = 2√15/16
sin2x = √15/8
for cos2x;
cos2x = 1-2sin²x
cos2x = 1-2(1/4)²
cos2x = 1-2(1/16)
cos2x= 1-1/8
cos2x = 7/8
for tan2x;
tan2x = tanx + tanx/1-tan²x
tan2x = 2tanx/1-tan²x
tan2x = 2(-1/√15)/1-(-1/√15)²
tan2x = (-2/√15)/(1-1/15)
tan2x = (-2/√15)/(14/15)
tan2x = -2/√15 * 15/14
tan2x = -30/14√15
tan2x = -30/7√15
rationalize
tan2x = -30/7√15 * √15/√15
tan2x = -30√15/7*15
tan2x = -2√15/7
