Question Number 81158 by ~blr237~ last updated on 09/Feb/20
$${S}=\frac{\mathrm{1}}{{cos}\mathrm{1}}+\frac{\mathrm{1}}{{cos}\mathrm{1}{cos}\mathrm{2}}+......+\frac{\mathrm{1}}{{cos}\mathrm{87}{cos}\mathrm{88}} \\ $$$${K}={tan}\mathrm{1}{tan}\mathrm{2}+{tan}\mathrm{3}{tan}\mathrm{4}+......+{tan}\mathrm{87}{tan}\mathrm{88} \\ $$