Help me with this question. This is the diagram. And I also include the question. Please help me .The question.
A=16π-8x+8π/4x^2
Find the value of x such that the value of A is minimum. Hence, find the minimum value of A.
I really hope you can help me please

In δabc, m∠acb = 90°, cd ⊥ ab and m∠acd = 45°. find: a find cd, if bc = 3 in

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Alex measured the length of an item to be 3.7 cm. the actual length is 3.5 cm. what is alex’s percent error?