`underset(x to 0)"Lt" (cos ax-cos bx)/(x^(2))=`

underset(x to 0)"Lt" (cos 5x-cos 3x)/(x^(2))=

underset(x to 0)"Lt" (1-2cos x+cos 2x)/(x^(2))=

underset(x to 0)"Lt" (1-cos(1-cosx))/(x^(4))=

underset(x to 0)"Lt" (1-cos 2x^(@))/(x^(2))=

underset(x to 0)"Lt" cos (1/x)=

underset(x to 0)"Lt" (x cos -log(1+x))/(x^(2))=

underset(x to 0)"Lt" (1-cos x)/(x^(2))=

If underset(x to 0)"Lt" ((cos 4x+a cos 2x+b)/(x^(4))) is finite, then the value of a, b are respectiveluy.

underset(x to 0)"Lt" (cos x+a sin bx)^(1//x)=