Question

please sole this question

Answer 1

CosA=2/5
TanA= √21/2
4+4(√21/2)²
4+21
25

Answer 2

$4 + 4 {tan}^{2} \\ 4(1 + {tan}^{2} ) \\ 4( {sec}^{2} ) \\ 4(1 \div {cos}^{2} ) \\ 4( {5}^{2} \div {2}^{2} ) \\ 4 \times 25 \div 4 \\ 25$
25 is the answer