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