7. Tаke tо be the reаl vectоr spаce оf polynomials of degree less than or equal to 3, that is, polynomials of the form , where some of may be 0. Recall that a real-valued function on is linear if it is additive and homogeneous. Decide whether the following real-valued functions on are linear. If so, check necessary conditions. Otherwise, show which condition is broken. a) ; b) .