How can I from the following cosine inequality
cosq1.cosq1 + cosq2.cosq2 +cosq3.cosq3 - 2 cosq1.cosq2.cosq3 - 1 ≤ 0
Drive the following inequality
cosq1 cosq2 – sqrt[(sinq1.sinq1)(sinq2.sinq2)]≤ cosq3 ≤ cosq1 cosq2 +
sqrt[(sinq1.sinq1)(sinq2.sinq2)]
sqrt == square root
Please help