Determine the value(s) of θ (between 0 and 2π) where tan(θ)=1. θ=

Determine the value(s) of θ (between 0 and 2π) where tan(θ)=−1.
θ=

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There is a linear relationship between a salesperson sales and her weekly income.if her sales are $200 her income is $500 and if her sales are 1,200 her income is $600.what is the relationship between sales and income