The surface 5 cm, and the length is 10 cm
Recall that
d/dx sech(x) = - sech(x) tanh(x)
d/dx tan⁻¹(x) = 1/(1 + x²)
Then by the chain rule,
dy/dx = - sech(x) tanh(x) / (1 + x²)

According to given figure, The Triangle BDC is a right angled Triangle (Angle D = 90°)
So, we can apply Pythagoras theorem to find the Side a (Hypotenuse)
Now, let's solve ~
Therefore, Length of side a is 5 units ~
Answer:
y=14
Step-by-step explanation:
because I solved it and got 14 ......