1. A signal space consists of four signals si(t), S2(t), S3(t), and S4(t) as shown below. a) Are the basis functions (Q1(t) and (Q2(t) orthonormal? Show your work. b) Represent si(t), S2(t), S3(t), and S4(t) geometrically in vector space using the basis functions (Q1(t) and Q2(t). S₁(1) 1 $2(1) 1- $3(1) 0.5 |$4(1) A F F A 0 -0.5- 1 0 -0.5 41(1) (a) 4₂(1) 1.0. (b) 2 0 1 2 1 Figure 1. Signals and their corresponding basis functions.