O valor de: $${\mathrm{tg}}^{10}x-5{\mathrm{tg}}^{8}x{\sec }^{2}x+10{\mathrm{tg}}^{6}x{\sec }^{4}x-10{\mathrm{tg}}^{4}x{\sec }^{6}x+5{\mathrm{tg}}^{2}x{\sec }^{8}x-{\sec }^{10}x$$para todo $x\in [0,\pi /2[$ é: