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>
Your answer for rounding 2.8497 x 10^3 is correct: 2.85 x 10^3.
350.0 is not correct because it has 4 sig figs. The proper rounding would be simply 350. with not additional zeros.
Answer:
Step-by-step explanation:
The rectangle has 4 corners of 90 degrees.
Here a rectangle is divided into two right triangles. In right-angled triangles, the opposite side at a 30-degree angle is half a chord...I replace x instead of length.. So x / 2 = 4--->x:8
The perimeter of a rectangle is equal to (length + width) × 2--->(8+4)×2=24m^2
