Evaluate the limits

Question

Help me please thanks sirs

Answer 1

7a) cos(1)=0.54 approx b) -1/π=-0.3183 approx c) -cos(1)=-0.54 approx

8a) 2 b) 0 c) 1/6; let x=9+h; limit becomes h➝0 for (√(9+h)-3)/h=(3√(1+h/9)-3)/h=(3(1+h/18)-3)/h=1/6

9a) 0 b) 0 c) 0