Remember:

$\boxed{sin(2x)=2.sinx.cosx}\\
\\
and\\
\\
\boxed{cos(2x)=cos^2x-sin^2x}$

$\frac{2cos2x}{sin2x}-cotx-tanx=\\
\\
\frac{2(cos^2x-sin^2x)}{2sinx.cosx}-\frac{cosx}{sinx}-\frac{sinx}{cosx}=\\
\\
\frac{cos^2x-sin^2x}{sinx.cosx}-\frac{cosx}{sinx}-\frac{sinx}{cosx}=\\
\\
\frac{cos^2x-sin^2x-cos^2x-sin^2x}{sinx.cosx}=\\
\\
\frac{-2sin^2x}{sinx.cosx}=\\
\\
\frac{-2sinx}{cosx}=-2.tanx$

4 0

3 years ago

If a cup of coffee has temperature 95∘C in a room where the temperature is 20∘C, then, according to Newton's Law of Cooling, the

muminat

Answer:

61°C

Step-by-step explanation:

Newton's Law of cooling gives the temperature -time relationship has:

T (t) = 20 + 75 е⁻(t/50)-------------------------------------------------------- (1)

where Time is in minutes (min) & Temperature in degree Celsius (°C)

During the first half hour, t = 30 mins

Substituting into (1)

T = 20 + 75 е⁻(30/50)

= 20 + 75(0.5488)

= 20 + 41.16

= 61.16°C

≈ 61°C

4 0

3 years ago

The minimum value of 2x + 1 is 13

Tamiku [17]

Hi Jalansmith133!

$
2x+1 = 13 \\ \\
2x = 12 \\ \\
x = 6
$

GoodLuck...

8 0

3 years ago