Is `frac{5}{9}`equal to `frac{4}{5}`?

Prove that Cos frac{pi}{5} + Cos frac{2pi}{5} + Cos frac{6pi}{5} + Cos frac{7pi}{5} = 0

cos frac{3pi}{4}-iota sin frac{3pi}{4}

solve the equations: frac{2}{sqrt x} + frac{3}{sqrt y} =2 and frac{4}{sqrt x} - frac{9}{sqrt y} =-1

frac{1}{sqrt7-4} frac{1}{sqrt11-7}

x frac{dy}{dx} = y - xcos^2 frac{y}{x}

frac{dP}{dx} = frac{d}{dx} (x^3) (frac{7-2x}{3})^(4)

if y= x^m then Y n is equal to: (A) frac{m!}{m-n!} x^(m-n) (B) frac{m!}{n-m!} x^(m-n) (C) frac{n!}{m+n!} x^(m+n) (D) frac{n!}{n-m!} x^(m-n)

Sameera purchased 3 frac{1}{2} kg apples and 4 frac {3}{4} kg oranges. What is the total weight of fruits purchased by her?

If z(x+y)= x^2 +y^2 show that (frac{delz}{delx}-frac{del z}{del y})^2 = 4 (1- frac{delz}{delx}+frac{delz}{dely})

Simplify the following 3frac{1}{7}-{1/6 xx (4div 3frac{1}{2}-7)}