Given data
<span>sin (x+pi/2)=cos x
</span>now using sin law
sin(a+b)=sin(a)cos(b)+cos(a)sin(b)
now using above values
sin(pi/2+x)=sin(pi/2)cos(x)+cos(pi/2)sin(x)
as we know that
sin(pi/2)=1
cos(pi/2)=0
now putting these values
sin(pi/2+x)=1*cosx+0*1
sin(pi/2+x)=cosx
hence proved that
<span>sin (x+pi/2)=cos x</span>
Answer:
I think the sides of polygon are 6
Step-by-step explanation:
Because to form a polygon we need to the first to form a horizontal and vertical line,to find the number in that line,and join the line based on the numbers given, then you will get a polygon with 6 side
Answer:
3)x=-9
4)x=-2
5)x=-4
6)x=-5
7)x=-12
8)x=-11
Step-by-step explanation:
Do you remember when you were learning about
Least Common Multiple (LCM) ? And you were
wondering what on Earth you would ever need it for ?
THIS IS IT !
The amount of time after 8 PM when the lights will flash
together again is the LCM of 20 seconds and 30 seconds.
Do you remember how to find it ?
... When 20 is prime-factored, you have 2 · 2 · 5 .
... When 30 is prime-factored, you have 2 · 3 · 5 .
... So the Least Common Multiple of 20 and 30 is 2 · 2 · 3 · 5 = 60 .
The lighthouses will flash together again in 60 seconds after 8 PM.
That'll be 8:01 PM.
3x+17=2x+23
5x=40
40/5=8
x=8
