If the minimum and the maximum values of the function f:π4, π2→R defined by fθ=−sin2θ−1−sin2θ1−cos2θ−1−cos2θ11210−2are m and M respectively, then order pair  (m, M) is equal to

fθ=−sin2θ−1−sin2θ1−cos2θ−1−cos2θ11210−2 R1→R1+R2+R3=1170−cos2θ−1−cos2θ11210−2 R3→R3-R1=1170−cos2θ−1−cos2θ113−2C1→C1-C1-C3 =4700−1−cos2θ103−2=42+2cos2θ−3=4cos2θ2θ∈π2,π⇒cos2θ∈−1,0⇒4cos2θ∈−4,0, m=-4 ,M=0