Given the polynomial P(x)=2x3−3x2+4x−5 and Q(x)=x−1, find the remainder when P(x) is divided by Q(x). Additionally, if R(x) is the remainder and θ is the root of Q(x), find the value of cos(θ) if R(θ)=cos(θ)
Step 4: Since it's given that R(θ)=cos(θ), we have cos(θ)=−2
Step 1 :Step 1: Divide P(x) by Q(x) using polynomial long division. This gives us P(x)=Q(x)⋅(2x2−x+5)+R(x), where R(x) is the remainder.
Step 2 :Step 2: Set Q(x)=0 to find the root θ, we have x−1=0 which gives θ=1
Step 3 :Step 3: Substitute θ=1 into R(x), we get R(1)=2⋅13−3⋅12+4⋅1−5=−2
Step 4 :Step 4: Since it's given that R(θ)=cos(θ), we have cos(θ)=−2