I'm only going to alter the left hand side. The right side will stay the same the entire time
I'll use the identity tan(x) = sin(x)/cos(x) and cot(x) = cos(x)/sin(x)
I'll also use sin(x+y) = sin(x)cos(y)+cos(x)sin(y) and cos(x+y) = cos(x)cos(y)-sin(x)sin(y)
So with that in mind, this is how the steps would look:
tan(x+pi/2) = -cot x
sin(x+pi/2)/cos(x+pi/2) = -cot x
(sin(x)cos(pi/2)+cos(x)sin(pi/2))/(cos(x)cos(pi/2)-sin(x)sin(pi/2)) = -cot x
(sin(x)*0+cos(x)*1)/(cos(x)*0-sin(x)*1) = -cot x
(0+cos(x))/(-sin(x)-0) = -cot x
(cos(x))/(-sin(x)) = -cot x
-cot x = -cot x
Identity is confirmed
Answer:
435.2kg (1DP)
Step-by-step explanation:
0.64x680
64 divided by 100 = 0.64
Factoring, you have
h(t) = -16(t^2 -2 -8) = -16(t -4)(t +2)
The ball hits the ground when h(t) = 0, so
0 = -16(t -4)(t +2)
t = 4 or -2
The positive solution is the one of interest.
It will take 4 seconds for the ball to hit the ground.
Answer:
C
Step-by-step explanation:
(2x-3)(4x+5)
=2x(4x+5)-3(4x+5)
=8x^2+10x-12x-15
=8x^2-2x-15