First we use sin(a+b)= sinacosb+sinbcosa
and cos(a+b)=cosa cosb -sinasinb
tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)
and sin(x+pi/2) = sinxcospi/2 + sinpi/2cosx =cosx,
<span>cos(x+pi/2) = cosxcospi/2- sinxsinpi/2= - sinx,
</span> because <span>cospi/2 =0, </span>and <span>sinpi/2=1
</span><span>=tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)= cosx / -sinx = -1/tanx = -cotx
</span>from where <span>tan(x+pi/2)=-cotx</span>
Answer:
its 7/9
Step-by-step explanation:
you just have to flip the fractions
-5 + 7= 7 + (-5) they are the same just switched
Answer:
6 crackers, 9 marshmallows
Step-by-step explanation:
You have to divide to find how many graham crackers and marshmallows are needed to make 1 s'more:
8 / 4 = 2, so 2 crackers per s'more. Then,
12 / 4 = 3, so 3 marshmallows per s'more. Now that we know this, all we have to do is multiply each number by 3 to make 3 s'mores.
2 * 3 = 6, so 6 crackers, and
3 * 3 = 9, so 9 marshmallows.
:)
