Mark the correct alternative in the following:

If and then α + β is equal to

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If A – B = π /4, then (1 + tan A) (1 – tanB) is equal to

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The maximum value of is

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If and tan A tan B = 2, then

Mark the correct alternative in the following:

If tan 69^o + tan 66^o – tan 69^o tan 66^o = 2k, then k =