=[(sinx/cosx)/(1+1/cosx)] + [(1+1/cosx)/(sinx/cosx)]
=[(sinx/cosx)/(cosx+1/cosx)]+[(cosx+1/cosx)/(sinx/cosx)]
= [sinx/(cosx+1)] + [(cosx+1)/sinx]
= [sin^2x+(cosx+1)^2] / [sinx (cosx+1)]
= [2+2cosx] / [sinx(cosx+1)]
=[2(cosx+1)] / [sinx (cosx+1)]
= 2/sinx
= 2 cscx
(I think this will be helpful for you. if you can see the picture, it has more detail in it.)
X+y+z=51
y=2z
z=9+x
subsitute those
x+2z+9+x=51
x+2(9+x)+9+x=51
x+18+2x+9+x=51
4x+27=51
minus 27 both sides
4x=24
divide by 4
x=6
sub back
z=9+x
z=9+6
z=15
y=2z
y=2(15)
y=30
the numbers are
6,30,15
Volume of a sphere is 4/3(pi r ^3)
You were given d = 10 so r = 5
Then just plug and chug
A coefficient is the number that is multiplied by the variable (the letter).
so the coefficient in ur expression is 3.
the 2 and the 4 are constants...because they are numbers with no variables