(x^2+y^2)^-1/(x^-2+y^-2)^-1
2.Without using a calculator, find the values of the following expressions and give the answers in integers or fraction
(a) a^7b^-13/b^2
(b) (a^2b^-3)^3/b^5
(c) (m^-3n^2)^-2/m^2n^3
更新1:
仲有一題: In each of the following conditions of triangle ABC,can we fix the triangle? Explain your answer (a) AB=5 cm, BC=6cm, angle A=90度 (b) AB=6 cm, angle B=93度, angle C= 57度